A convicted pedophile who advertised as a babysitter and abused two little girls while on probation near Chilliwack, B.C. was killed during a prison riot late Saturday night.

Michael Gibbon, 39, was killed by other inmates at Mountain Institution in Agassiz, some 16 years after he was first convicted of molesting an infant, and some 10 years after his botched case sparked a review of how police handle sex offenders.

As a free man, Gibbon -- a heavy-set labourer with the intelligence of a 15-year-old -- lived in a small room in his parents' home in Bridal Falls and worked at a nearby chicken farm with his mother.

But while spending hours alone in his room with his computer, he used the nickname "Natasha" to solicit photos of nude children and lure young victims, and spliced the images together with Disney movies.

Gibbon was serving an indeterminate sentence for sexual offences at Mountain Institution, a federal male medium security prison located about 120 kilometres east of Vancouver. It houses 442 inmates.

At about 9:45 p.m. inmates in the gymnasium started to break windows, and threatened staff and assaulted other prisoners.

While one other person was injured in the riot and taken to hospital, no staff members were hurt, prison officials said. A lockdown will continue and prisoners will be searched while officials try and find out the cause of the riot.

As early as 1992, Gibbon told a forensic psychiatrist that he was sexually abused by an elementary school janitor and by another student. Gibbon in turn began abusing younger children and classmates, the psychiatrist told a hearing.

Throughout grades 4 to 6, he touched girls in the breast and vaginal areas, despite repeated warnings from teachers.

But when he was charged and convicted with molesting a child in 1992, he was released with minimal supervision after three months in prison.

Although police felt he was a risk to reoffend, residents of Bridal Falls were never told that Gibbon -- who advertised that he would babysit toddlers for free -- was a convicted pedophile.

For some five years after he was released, Gibbon made at least 488 videotapes where he interspersed "freeze-frame" shots of nude toddlers with scenes from Disney movies and kid's television shows, court heard.

He also took photographs of two young girls aged three and five, who he babysat. He was banned from taking videos at two local amusement parks -- including one where in 1987 he had been accused of sexually assaulting an eight-year-old.

And some of the 53 rolls of film that police eventually seized showed Gibbon having sex with the two toddlers and showed acts of bestiality.

He was caught in a sting operation in 1997 by the U.S. treasury department, which offered child pornography for sale and offered a discount to people who could provide pornographic photos involving children.

Even behind bars awaiting trial, Gibbon cut out pictures of naked, prepubescent children, court heard before it decided to classify Gibbon as a dangerous offender, which meant that Gibbon had an indefinite jail term.

Ujjal Dosanjh, the attorney-general of B.C. at the time, launched an investigation into whether Chilliwack police mishandled the incident.

The investigation discovered that case notes weren't properly kept, and while two probation officers had special expertise in dealing with sex offenders, the local director kept the case to himself.

The investigation resulted in more stringent supervision for sex offenders across the province.