Murderer Vincent Tabak kept images of children being sexually abused on his laptop computer, police have discovered.

The 33-year-old killer was jailed for life on Friday after a jury found him guilty of throttling 25-year-old Hampshire woman, Joanna Yeates.

Following his conviction at Bristol Crown Court it was revealed that the Dutch engineer was obsessed with images of women being strangled during sex and had perversions for violent pornography and prostitutes.

It also came to light that Tabak faced further questioning by police relating to material discovered on the hard drives of computers he used.

It has now been reported that Avon and Somerset Police discovered 30 images of youngsters being sexually abused.

An officer involved in the investigation, who asked not to be named, told the Bristol Evening Post that he and his colleagues wanted to clear up speculation surrounding these ''other matters''.

He said: ''Tabak had 30 images depicting child pornography on his laptop computer at home.

''They were all category four images.''

The officer said that, due to Tabak's conviction for murder and life sentence, he did not think the Crown Prosecution Service would take action.

There are five levels of seriousness for offences involving indecent photographs of children, which start with images depicting ''erotic posing with no sexual activity''.

Category four images depict penetrative sexual activity involving a child or children, or both children and adults.

Detective Chief Inspector Phil Jones, who led the murder investigation, confirmed: ''During the examination of Vincent Tabak's computer, other material was found.

''We have referred this matter to the Crown Prosecution Service for initial guidance.''

Once referred to the CPS they will consider a number of criteria before charging someone with an offence.

This includes whether it is in the public interest to do so.

Jurors in Tabak's trial were not told that videos found on his computers had chilling parallels with the way Miss Yeates died.

His pornography depicted blonde women being throttled during sex or bundled into car boots.

Two weeks before murdering the landscape architect, he also paid for sex with a prostitute during a business trip to Los Angeles.

But despite being blocked from hearing of his depraved sex secrets, jurors still found him guilty of murdering his next-door neighbour on December 17 last year.

The frozen body of Miss Yeates, who lived with her boyfriend, Greg Reardon, in a flat in Canynge Road, Clifton, Bristol, was found on Christmas morning by a couple walking their dog on a country lane in Failand, North Somerset.

Tabak was jailed for life by Mr Justice Field and told he would serve at least 20 years in prison before he could apply for parole.