Stephen Lawrence police corruption probe near completion

The Independent Police Complaints Commission (IPCC) has interviewed former detective turned whistleblower Neil Putnam several times about allegations made in a BBC documentary, a spokeswoman said.

But the organisation has not yet made a final decision on whether it will seek to interview the man alleged by the programme to have acted corruptly in the original 1993 investigation.

It is examining whether ex-detective sergeant John Davidson had a corrupt relationship with Clifford Norris, the father of one of the murder suspects.

Mr Davidson, who now runs a bar in Spain, has firmly refuted the allegations against him in the programme last summer.

The IPCC is also examining whether corruption claims were reported to the Metropolitan Police and not properly investigated.

IPCC deputy chairman John Wadham said: "We expect to conclude the investigation by the summer, when we will publish the results of our inquiry on our website.

"We are doing everything within our power to find out the truth about these allegations."

He added: "However, investigating corruption charges that are alleged to have occurred 13 years ago is extremely challenging.

"The passage of time has made it difficult to identify witnesses and to locate relevant evidence amongst the large volume of material that exists.

"This has resulted in the investigation taking longer than we had wanted.

"Having said that, our inquiry has made progress, including examining related investigations conducted by other bodies and identifying relevant material."

An IPCC spokeswoman said interviewing Mr Davidson remained a possible line of inquiry but no decision had yet been made.

If it uncovers any evidence of corruption, the IPCC may make recommendations regarding possible criminal proceedings.

Stephen, an 18-year-old A-Level student, was stabbed to death at a bus stop in Eltham, south-east London, in an unprovoked race hate attack by a gang of five white youths in April 1993. A bungled police investigation followed.

No-one has been convicted of the killing but five men - Neil Acourt, his brother Jamie, David Norris, Gary Dobson and Luke Knight - were arrested soon after the event.

Three of the men were acquitted of murder after a private prosecution brought by the Lawrence family collapsed at the Old Bailey in 1996.

In the documentary, The Boys Who Killed Stephen Lawrence, Mr Putnam claimed Mr Davidson was receiving a "nice little earner" from Clifford Norris to put him one step ahead of the investigation.

Mr Davidson later issued a statement in which he refuted the "devastating and false" allegations against him.

He insisted he was not corrupt, that he had not hampered the Lawrence investigation "in any way" and described the claims as "extremely upsetting".

The IPCC launched the inquiry on the programme's broadcast last July.