One of Britain's most prolific child sex offenders, Richard Huckle, has been stabbed to death in prison while serving a life sentence for abusing Malaysian and Cambodian children.

Key points: Richard Huckle, 33, abused children and babies over a nine-year period

Richard Huckle, 33, abused children and babies over a nine-year period He was sentenced to life in prison in 2016 after pleading guilty to 71 offences

He was sentenced to life in prison in 2016 after pleading guilty to 71 offences Police found over 20,000 images of child sex abuse and rape when he was arrested

Huckle, 33, who abused children and babies over a nine-year period, was sentenced in a London Court to life in prison in 2016 after pleading guilty to 71 offences.

His crimes were discovered by the Queensland Police Force's Task Force Argos child protection unit, targeting online paedophiles, which passed on the information it gathered to the UK's National Crime Agency, leading to Huckle's arrest in 2014.

During the arrest, UK police found his laptop and camera, which contained more than 20,000 images of sexual abuse, including rape.

He was found stabbed to death in his prison cell on Sunday, the BBC reported. He had been attacked with a makeshift knife.

Police have launched an investigation.

"HMP Full Sutton prisoner Richard Huckle died on 13 October," a prison service spokesman said, referring to the high-security jail where Huckle was being held.

"It would be inappropriate to comment further while a police investigation is ongoing."

Full Sutton prison is a maximum security prison for men that holds "some of the most difficult and dangerous criminal in the country", according to the Ministry of Justice website.

Arrested after Queensland Police sting

Using the pretext of being a photographer, English teacher and Western philanthropist, Huckle won the trust of impoverished families before carrying out the abuse.

Huckle's crimes included rapes, which he filmed, photographed and shared online with paedophiles worldwide.

He may have targeted nearly 200 children, aged between six months and 12 years, and boasted that those from poor communities made easier victims than well-to-do Westerners.

Task Force Argos investigators secretly took control of a child pornography site on the dark net in 2014 and identified several hundred sex offenders around the world, including Huckle.

They provided information about Huckle to detectives from the UK's National Crime Agency and he was arrested at Gatwick Airport shortly afterward.

He received 22 life sentences for his crimes and was told he must serve at least 25 years behind bars.

Huckle is one of the most prolific child sex abusers known to have operated in Malaysia, where the authorities have been criticised for failing to tackle sex crimes against children properly.

He also produced his own online paedophile manual advising others on how to abuse children and escape detection, described by trial judge Peter Rook as a "truly evil document".

ABC/Reuters