Nicknamed the "Yorkshire Ripper" by the UK press, Sutcliffe was convicted in 1981 for murdering 13 women and attempting to murder seven others during a reign of terror in northern England between 1975 and 1980. He was serving a whole life term.

He had been suffering from underlying health conditions before testing positive for Covid-19, but the Prison Service could not confirm the cause of death as that is "rightly a matter for the coroner."

A Prison Service spokesperson said: "HMP (Her Majesty's Prison) Frankland prisoner Peter Coonan (born Sutcliffe) died in hospital on 13 November. The Prisons and Probation Ombudsman has been informed."

Sutcliffe spent many years in Broadmoor high-security psychiatric hospital, before being considered stable enough in 2016 to be transferred to Frankland prison in County Durham, Britain's PA news agency said.

He confessed to police in 1981 but then decided to contest the charges in court. During his trial at the Old Bailey in London he claimed he was on a mission from God to kill prostitutes.

Sutcliffe was born in June 1946 in Bingley, West Yorkshire. Among other jobs, he worked as a truck driver and grave digger.

He carried out his first killing in October 1975, less than a year after he was married. The victim was 28-year-old Wilma McCann, a mother-of-four and sex worker. She was battered with a hammer and repeatedly stabbed.

"After that first time, I developed and played up a hatred for prostitutes in order to justify within myself a reason why I had attacked and killed Wilma McCann," Sutcliffe later told police.

Other victims followed over the course of the next five years, including 42-year-old Emily Jackson and 16-year-old Jayne MacDonald.

'Heartfelt apology'

Sutcliffe was questioned several times by police in the course of their investigation but a series of blunders and a hoax that led detectives to focus their search for a suspect on the wrong area of northern England allowed him to carry on killing undetected.

He was finally arrested in January 1981 after police stopped the car he was driving, having found the number plates were stolen. He had picked up street worker Olivia Reivers as a passenger. Detectives later found a hammer and knife nearby.

In May 1981 Sutcliffe was jailed for 20 life terms at the Old Bailey in London, with the judge recommending a minimum 30-year sentence.

His actions cast a shadow over the north of England for half a decade, with many women and girls afraid to go out after dark.

West Yorkshire Police Chief Constable John Robins offered a "heartfelt apology" Friday to the women who survived Sutcliffe's assaults and victims' relatives for the language used by senior officers at the time of the investigation.

Richard McCann, the son of Sutcliffe's first victim, had previously called for a formal apology from police over the language used to describe those of his victims who were sex workers.

McCann told the Yorkshire Post newspaper it was unfair that police had referred to some of the women as having "doubtful morals" while they described MacDonald as an "innocent victim."

"On behalf of West Yorkshire Police, I apologise for the additional distress and anxiety caused to all relatives by the language, tone and terminology used by senior officers at the time in relation to Peter Sutcliffe's victims," Robins said in a statement.

"Such language and attitudes may have reflected wider societal attitudes of the day, but it was as wrong then as it is now."

'Closure' to victims' families

Robins also acknowledged that mistakes had been made by police as they investigated Sutcliffe's crimes.

"The investigation into offences committed by Peter Sutcliffe was, at the time, the largest ever conducted by a UK police force and was subject to two exhaustive reviews in the immediate aftermath," he said.

"Failings and mistakes that were made are fully acknowledged and documented. We can say without doubt that the lessons learned from the Peter Sutcliffe enquiry have proved formative in shaping the investigation of serious and complex crime within modern day policing."

A former police officer who worked on the case, Bob Bridgestock, told BBC Radio 4 earlier Friday that Sutcliffe "wasn't a very intelligent killer, he was just brutal," adding that he would be "detested" long after he was gone.

His death would bring "some kind of closure" to victims' families, he said. "The news today will bring back some very sad memories for a lot of them. And we should remember the victims, not the killer," he added.

Bridgestock acknowledged that mistakes were made by the police, saying senior officers "wore blinkers on the investigation," but also pointed to the limited resources available to investigators then.