At least three HSBC accounts affiliated with a Hong Kong Christian church have been frozen, a move the organisation called an “act of political retaliation” for its support for protesters during last year’s social unrest.

But police said an investigation into money laundering and fraud was under way, involving the Good Neighbour North District Church and how it had received HK$27 million in donations over more than a year but only publicly declared less than a third of the amount.

The church said in the early hours of Tuesday that its bank account, and those of pastor Roy Chan Hoi-hing and his wife, had been frozen without prior notification or justification.

Chan said the accounts were frozen while he and his family of five were on sabbatical in Britain, leaving them penniless.

Acting senior superintendent of the Narcotics Bureau’s financial investigation unit, Chow Cheung-yau, said on Tuesday evening that police told the bank on Monday to freeze five accounts involving HK$25 million on suspicion of money laundering and conspiracy to defraud.

Two Hong Kong women, aged 24 and 37, were also arrested on Tuesday in relation to the allegations. The younger suspect is a former director of the church, while the other is an existing employee.

Chow said the Chans, who are director and company secretary of the church, were wanted. The couple left Hong Kong in mid-October.

“We are chasing the flow of the money,” he added.

The police investigation is centred on online crowdfunding activities. Chow said police found that the church received HK$27 million in donations between June last year and September this year, and that it only publicly announced that HK$8.9 million was raised.

“We also found some spending did not match the original planned use of funds,” he said.

The church earlier said in a statement that the frozen accounts could be related to its Safeguard Our Generation ministry, an initiative in which middle-aged and elderly volunteers offered humanitarian aid to frontline protesters last year.

Volunteers of the ministry, more commonly referred to as “Protect the Children”, had attempted to mediate between protesters and police to de-escalate tensions during the protests.

“This is no doubt an act of political retaliation,” the church said in its statement, condemning HSBC. “The purge has never ceased, just like the asset-freezing case of the self-exiled [former] Democrat, Ted Hui and his family. Such [an] incident has severely eradicated dissent in Hong Kong, suppressing freedom among religions and community service workers.”

Hui, who recently jumped bail in Hong Kong to go into self-exile in Britain, has been engaged in a war of words with police over the freezing of bank accounts belonging to him, his wife and his parents at HSBC, Hang Seng Bank and Bank of China. Police said Hui and his family’s accounts were frozen as part of an investigation into money-laundering allegations also stemming from a crowdfunding campaign.

An HSBC representative said it was unable to comment on matters concerning specific accounts.

“We have to abide by the laws of the jurisdiction in which we operate,” the bank said. “Further inquiry should be directed to the related law enforcement agency.”

It is understood that Chan is one of the main holders of the church account.

Chan said he and his family were unable to return to Hong Kong, and that the trip to Britain was meant to be a working holiday.

“My family is with me right now in the UK, having a few months of vacation and looking at the chances of planting a church here,” he said. “My family of five is living on an empty wallet, and we are still figuring how we can take care of our kids, including one who is seven months old, and sustain our living here.”

Meanwhile, the church criticised HSBC for “exploiting the well-established independent financial system and sabotaging the benefits of individuals and groups of Hong Kong, as well as foreign investors within the territory”.

The church, which is registered as a charity, said the freezing of its account would force the immediate termination of its hostel services for the homeless. The church runs hostels in North district, Yuen Long and Kwun Tong that serve more than 70 people with the assistance of social workers.

“During the pandemic, the Social Welfare Department has approached our church several times, aiming to look for accommodation for the homeless. Freezing the church account would lead to immediate termination of the hostel service, inevitably forcing the homeless to be homeless again,” the church said, adding that its funds were raised from legal donations.

The church has launched a petition calling on HSBC to restore the bank accounts in question, attracting more than 19,400 signatures as of 9.15pm.