The police watchdog is to investigate whether officers ordered the destruction of documents which caused the collapse of a multimillion-pound police corruption trial.

Ten defendants, including eight former officers, were acquitted of fabricating a case which led to the wrongful imprisonment of three men for the murder of prostitute Lynette White following claims that files of evidence had been shredded.

However the documents were later discovered in the hands of South Wales Police.

During the trial, it was alleged that a top cold case detective had ordered papers submitted by the Independent Police Complaints Commission (IPCC) to be destroyed. Mr Justice Sweeney discharged the jury, telling them the accused could not get a fair trial.

The revelation prompted Director of Public Prosecutions, Keir Starmer QC, to order an independent probe into the disclosure exercise conducted by prosecutors involved in the case.

IPCC Commissioner Sarah Green said the watchdog's probe had been updated to reflect the discovery of the documents.

She said: "This is a very tightly focused investigation that concentrates on events regarding the alleged destruction of IPCC documents that were referred to in Swansea Crown Court. We are not investigating the reasons for the collapse of the trial, which is a matter for the Director of Public Prosecutions."

IPCC investigators aim to establish whether any decision was made to destroy four files by a police officer or staff member and, if so, whether the reasoning for such a decision was properly recorded. It also seeks to clarify what happened to the files prior to their discovery on January 17.

Detectives arrested Stephen Miller, Yusef Abdullahi, Tony Paris and cousins Ronnie and John Actie for murder after Miss White's body was found with more than 50 stab wounds. The cousins were cleared but the three other men went on to serve two years in prison before being released on appeal.

In 2003, Jeffrey Gafoor, a client of Miss White, admitted her murder and was sentenced to life behind bars. His admission was the catalyst for the investigation into the officers in the original case.