Essex Police is under investigation after the force allegedly returned a laptop containing “more than 100 indecent images” to a man who was later found guilty of rape.

The Independent Office for Police Conduct (IOPC) said it was looking into the force’s handling of the investigation.

In a statement, the IOPC said Essex Police had handed back computers that “may have contained more than 100 indecent images” to Paul Ashbury, 52, of King’s Lynn, Norfolk.

Ashbury was arrested by Essex Police in 2012 on suspicion of sexual assault against a child and possessing indecent images, and officers seized computers from him.

These were returned to Ashbury in 2013 when they decided to take no further action against him.

Ashbury was arrested by Norfolk Police in 2017 and earlier this year was jailed for 15 years after admitting offences including rape, sexual assault, sexual activity with a child and making indecent photographs of a child, the IOPC said.

“It appears when Norfolk Police officers examined Ashbury’s laptop they found additional child abuse images which it is believed had not been identified during Essex Police’s investigation,” the IOPC said in a statement.

The IOPC investigation will examine the conduct of officers from Essex Police’s child abuse investigation team (CAIT) and whether the investigation into Ashbury was carried out in accordance with the force’s policy, procedures and guidelines.

Sarah Green, IOPC regional director for the South East, said: “These are extremely serious allegations regarding how Essex Police investigated a man who later admitted multiple child sexual offences following the investigation by Norfolk Police.

“We will examine the officers’ actions and what if anything they could have done differently.”

A spokesperson for Essex Police said: “This investigation comes after Essex Police referred to the IOPC matters relating to a case from 2012. We are unable to comment in further detail at this stage but will of course comply fully with the investigation. Since this incident Essex Police has made significant improvements to policing of these offences and has invested heavily in more officers and better technology to identify offences and evidence and protect children.”