A liaison officer who has been at the side of the family of tragic schoolgirl Jessica Chapman throughout their ordeal was arrested yesterday over allegations involving indecent pictures of children.

Detective Constable Brian Stevens was held as part of an investigation into child porn on the Internet.

Last month, the officer read a poem, written by a friend of the Chapmans, at the memorial service for Jessica and Holly Wells in Ely Cathedral.

Another constable working on the inquiry into the deaths of ten-year-olds Jessica and Holly, both from Soham in Cambridgeshire, was also arrested.

Both officers are suspected of "inciting others to distribute indecent photographs of children" and were last night being questioned.

Police stressed the child pornography allegations were in no way linked to the murder investigation.

The arrests follow an internal inquiry by the Cambridgeshire force following allegations about the two officers.

West Midlands Police have now been asked by Cambridgeshire to carry out their own independent inquiry supervised by the Police Complaints Authority.

The officers' arrests were part of an investigation, codenamed Operation Ore, in which UK police have been targeting users of pay-per-view US websites.

In May, 36 people were arrested in raids co-ordinated by the National Crime Squad. Suspects were accused of paying to access websites which were selling pornographic images, some of them of children as young as five.