It was about midday on a Friday in late October when a rampaging mob stormed the Hutchison House headquarters of the Independent Commission Against Corruption (ICAC), in Central, brawling with staff and vandalising the offices. Five officials of the anti-graft agency were beaten up as the assailants smashed doors and windows and ripped the ICAC plaque off the wall.

That the attackers were police officers – both serving and retired – came as little surprise to those following the ICAC’s crusade to stamp out the rampant corruption that had spread its tentacles across the force.

“Details emerged which were quite shocking to all of us,” says former ICAC chief investigator Stephen Char Shik-ngor. “There was a certain amount of antagonism between the police and the ICAC, but nobody had expected such a public display of outright violence.”

Which raised the question: who really runs Hong Kong?

Given the city’s current, 20-plus weeks of upheaval, it’s as valid a question today as when these events took place, on October 28, 1977.

The ICAC was set up by the British colonial govern­ment in 1974, tasked with stamping out graft while educating the community about its evils. Corruption was a part of everyday life in Hong Kong and kept the wheels turning, and so it was known as heung yau(“fragrant grease”).

ICAC agents viewed the Royal Hong Kong Police Force as a prime target, charging high-ranking officers as well as the rank and file with taking bribes and colluding with criminals.

For their part, many chai loh (“police offi­cers”), both expatriate and local, regarded “tea money” as a perk of the job and viewed the ICAC’s sweeping investi­ga­tions as meddlesome and naive.

“Corruption was part and parcel of society at that time, a legacy of the way things had been done in China for centuries,” says Char, now 70 years old, who joined the ICAC in 1976. “The police were in daily contact with the public, so the opportunities for corruption were rife. But there was a strong feeling that the time had come to bring it to an end, and that was where the ICAC came in.”

Chris Emmett, a retired superintendent who now lives in Britain, describes a typical scene in his 2014 memoir, Hong Kong Police Man . As a recently joined inspector of the Royal Hong Kong Police Force, earning HK$1,400 a month in the early 1970s (which is comparable to a starting salary of up to HK$84,250 today), he was taken aside by a senior officer for a quiet man-to-man chat.

He pulled an envelope from his pocket and laid it on the bar; inside were two $100 bills. “Play the game, and you’ll get one of these every week,” he said.

“[This job is] like a bus. You can get on board or run alongside, [just] don’t stand in front of it.” Then he left, shutting the door behind him.

The opportunity to collect an extra half-month’s salary tax-free, and also be “part of the gang”, was a lure that many felt unable to resist. Cases such as that of chief superintendent Peter Godber – jailed for four years in 1975 after failing to explain how he had amassed a personal fortune of more than HK$4 million – and Lui Lok, aka “The HK$500 Million Sergeant”, who fled to Taiwan in 1973 and then on to Canada to avoid the Hong Kong authorities, were two of the most prominent.

By autumn 1977, the ICAC was closing in, much to the alarm of a substantial cohort of police officers who felt they had simply been following tradi­tion.

In the days preceding the storming of the ICAC head­quarters, four superintendents and 45 officers and other ranks had been hauled into court on corruption charges. On the morning of October 28, 4,000 off-duty officers massed at Police Headquarters, in Central, to present a petition signed by two-thirds of the 17,000-strong force to the then-commissioner, Brian Slevin, deriding ICAC methods, in particular the use of convicted criminals as witnesses.

The petitioners also objected to the ICAC’s tactic of catching culprits groggy, during dawn home raids, and complained that the agency “seemed to have its own rules”. Observers at the time commented that the same could well be said of the Royal Hong Kong Police Force.

Soon after representatives had met Slevin, a breakaway group of about 40 marched to Hutchison House, besieging the ICAC’s sixth-floor offices. An eyewitness recalled, “The [policemen] abused the ICAC men and […] about seven of them surrounded a European who crouched in a corner and tried to shield his head as they threw punches.”

Flower pots were hurled at glass panels and the ICAC plaque was ripped off and stomped on. Once the policemen had left, five ICAC investigators, bloodied and dishevelled, limped off in search of medical treatment. A bystander asked if the incident would be reported to the police. “That’s a laugh,” one replied.

Ironically, one ICAC staffer had already dialled 999 and a uniformed patrol unit arrived at about 12.30pm, but the fracas was over. During the next few days, ICAC offices were subjected to a flurry of bomb hoaxes and bodyguards were assigned to senior officers.

“I remember the day of the assault on the ICAC head­quarters clearly,” says Char, sitting comfortably in his Lippo Centre office, in Admiralty, overlooking the People’s Liberation Army headquarters. “I was off-duty at the time and went to the cinema in Yau Ma Tei.

“When I came out, everyone on the street was talking about what had hap­pened, so I returned to my office in Sheung Wan – I was working in the community relations division at the time – to see what I could find out. In the following days, events took a seismic shift that changed everything for the ICAC and many of those they were trying to bring to justice.”

The governor, Murray MacLehose, and ICAC com­missioner, Jack Cater, were caught between two scenarios. If they let the ICAC continue with its investiga­tions unchecked, Hong Kong could face a wholesale revolt by the police, who were widely regarded as doing their job more or less satisfactorily.

But if they backed down, it would call into question both the government’s authority and its drive against corruption. The authorities’ predica­ment was not too far removed from the current situation as protesters and police battle each other on the streets and wage their own PR wars in cyberspace.

When MacLehose and Cater met with the commander of British forces, Lieutenant General John Archer, they gave serious consideration to a proposal to mobilise British troops stationed in Hong Kong.

Such a move, though, was discounted for fear that the sight of armed foreign soldiers on the streets would send shock waves through the eco­nomy, which had taken considerable time to recover from the 1960s riots. In the end, the governor and his aides settled on a precarious compromise.

On November 5, just over a week after the attack on Hutchison House, MacLehose offered a partial amnesty – the ICAC would drop investigations into offences committed before January 1, 1977, though exceptions were to be made for “heinous” crimes, a definition left for the governor to decide.

As far as the chai loh were concerned, they had been let off the hook. Celebratory drinking sessions that lasted long into the night resounded with chants of “police power”.

One 20-year veteran offered a tongue-in-cheek comment to the South China Morning Post: “Corruption used to be universal. Everybody had to either take part or have knowledge that others were taking part. There was no alternative. But the sins of the past should not be held against people still serving in the force.”

Char, who qualified as a barrister after leaving the ICAC, says: “The announcement of a partial amnesty was a huge blow to morale, as everyone in the ICAC felt they had worked so hard to battle some­thing that was ingrained in society and now corrupt offi­cials were going to get away with it. Were we just going to become a toothless tiger?”

The ICAC’s subsequent annual report stated: “The immediate effect of the partial amnesty on the work of the Operations department was that 83 investigations into offences committed prior to 1st January 1977 had to be terminated.

“These cases ranged from those involving single individuals to corruption syndicates in which large numbers of people were alleged to have participated. The exceptions to the amnesty and the cases opened since January 1977 left the Operations department with a caseload of 203.”

The report also recorded that by the end of 1977, the ICAC had investigated 386 police personnel and prosecuted 126, figures that compare starkly with 295 investigations and 33 prosecutions for all other govern­ment departments combined.

“Before the ICAC came into being, police stations were often covertly organised by the station sergeant and his syndicate, who would levy a regular fee on whoever was running the local drugs, gambling and prostitution rings,” recalls Char.

“One policeman would be responsible for collecting the money, which was then shared among the syndicate. Any officer who didn’t join the syndicate would gradually find himself frozen out by the others and subsequently posted elsewhere. The station sergeants made millions.”

Not surprisingly, on the Hong Kong Police Force’s website, under the Police History tab, “Chapter 3 Creating a Legend – 1967-1994” neglects to mention the assault on the ICAC headquarters and skips straight from the protest to the amnesty. Once the ICAC had made a number of prosecutions, the police were at liberty to start burnishing their new-found image.

“In the following months, ICAC officers slowly came around to accepting the new order,” says Char. “It was not going to be possible to bring all those who had behaved improperly in the past to justice, but at least we could strive for the future. We just had to accept the fact that no society is perfect.”

The amnesty dealt the ICAC’s reputation a severe blow, and the number of reports of corruption dropped sharply. But public confidence gradually returned as people realised the graft busters were still intent on to their role.

“The police force underwent some serious changes in the following years,” says Char. “They started to recruit officers with a better standard of education – previously, pretty much all they had to do was an elementary dictation test. Pay and conditions improved. And we met with senior officers and convinced them that corruption was not just something we had to root out, it was their problem, too.”

Over time, the police force was able to build up a repu­tation as “Asia’s finest”. They were aided by a sequence of events in which they were able to perform their job both in the public eye and to public acclaim.

In February 1979, the freighter Skyluck docked in Victoria Harbour, carrying more than 2,600 Vietnamese refugees. The police were largely responsible for dealing with both this and other ships transporting “boatpeople”, bolstering their reputation as guardians of law and order.

In the 1990s, when triad gangsters and other oppor­tunists toting automatic weapons staged brazen daylight robberies in the city – shooting at will and on one occasion blithely hailing a taxi to make their getaway – the media carried images of police swarming the scene, armed and in protect-and-serve mode, heroic cops putting their lives on the line to safeguard Hong Kong.

“Until recently, the police force could lay claim to being one of the best in the world,” says Char, who was among the 3,000 lawyers who marched in June to protest against the extradition bill. “A reputation such as that takes years to build and it only takes a short while to lose it. It’s a police officer’s job to bring offenders to justice, but it’s up to the courts and the law to administer it.

“You see the police now being reviled by many sections of society. It’s as if all the hard work that has gone into building up Hong Kong as a pillar of law and order has gone to waste and we have returned to the dark days of 1977.”

The police and the Independent Commission Against Corruption have provided rich source material for tele­vision and cinema. This year marks the 10th anniversary of Wong Jing’s crime drama I Corrupt All Cops (Gam Chin Dai Gwok), which saw Tony Leung Ka-fai play a crooked cop brought to book by the ICAC.

The disclaimer at the start of the film – to the effect that it depicts the bad old colonial days rather than the squeaky clean Hong Kong of the new millennium – is widely believed to be laced with irony.

However, 2002’s Infernal Affairs and its sequels – Andrew Lau Wai-keung and Alan Mak Siu-fai’s tightly plotted crime thriller tracing the fine line between police and triad societies – remain the pre-eminent Hong Kong cop flicks, and are arguably among the best films ever made in Asia.