A chief constable could face jail and an end to his 35-year police career for defying a High Court order to return computers suspected of holding a huge collection of child abuse images to a controversial expert witness.

Colin Port, Chief Constable of Avon and Somerset, was served with a High Court summons alleging contempt of court at his force headquarters yesterday. But Mr Port is adamant that he will not return 87 hard drives and 2,500 photographs of abuse seized from the home of Jim Bates, a forensic computer analyst.

Senior police sources told The Times yesterday that Mr Port believes that returning the material before it is analysed and investigated would be “tantamount to a neglect of duty”.

One said: “He thinks the public would be appalled if he were to hand over these hard drives, which are suspected of containing images of child abuse, without examining them with a view to identifying the children, rescuing them and preventing any further abuse.”

Avon and Somerset Police’s inquiry into Bates began last year, soon after he provided a statement as an expert witness for the defence in the case of a Bristol man charged with possessing child abuse images that went to court in September 2008.

Bates, 68, is seen by some as the founding father of forensic computer analysis but his credibility was undermined when he was convicted in March last year of falsifying his qualifications and given a six-month suspended prison sentence.

Police and prosecutors were concerned when, despite his conviction, Bates obtained a copy of the suspect’s computer hard drive by saying that he was an assistant to a defence witness.

The computer expert was investigated on suspicion of conspiring to possess indecent images of children and police obtained a warrant from magistrates to search his home. A haul of material — hard drives, memory sticks and hard copy images — was seized from Bates’s home in Leicestershire by Mr Port’s officers in September last year.

Lawyers for Bates sought a judicial review of the legality of the search of his home and won a High Court ruling that the warrant obtained by police was not properly obtained. Two judges said that the search warrant was illegal because the police did not inform the magistrate who granted it that Bates’s possessions might include legally privileged material relating to other court cases.

The effect of that ruling was to require Avon and Somerset Police to halt their investigation into Bates and return the material taken.

Mark Spragg, Bates’s solicitor, said: “You cannot simply take legally privileged material or special procedure material — the police failed to tell the magistrate that Mr Bates had acted as a prosecution and defence expert many times.

“The High Court therefore made an order for the return of the material. Mr Bates needs that order to carry out his job as an expert computer analyst and the material is currently being withheld from him illegally.”

As a pioneer of forensic computer analysis, Bates has been used widely by police and prosecutors in the past. He has lectured at police training colleges. The authorities became concerned about his retention of material from court cases, but Mr Bates argued that he had to retain casework in case of future appeals.

The Crown Prosecution Service said Bates was no longer used as an expert witness and that confidential guidance concerning him had been issued to all prosecutors in 2006.

Bates fears that he is being targeted by police because he has become an outspoken critic of the conduct of Operation Ore, a nationwide police investigation into online child abuse that began in the late 1990s and led to thousands of arrests.

The expert had helped in the prosecution of a number of early Operation Ore cases before expressing his concerns about the inquiry. He is now assisting people who are appealing against their convictions and another group who are taking civil action.

Papers from Bates’s work on the Operation Ore appeals are understood to be among the material seized by police that he wants returned.

Tony Butler, a former spokesman on child protection for the Association of Chief Police Officers, said he understood why police would need to retain and examine images of abuse. He said: “Technology has advanced to such an extent that we can gain a lot of clues from a photograph. It is possible to identify a child, where the abuse took place and possibly prevent further abuse.”

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