British Special Forces did not play a role in the death of Princess Diana, a probe by police has concluded.

There is "no credible or relevant evidence" which points to a conspiracy to kill Diana involving elite SAS troops.

Police opened an investigation in to the claim earlier this year, after a former sniper in the crack unit alleged that SAS troops caused the crash in a Paris tunnel which killed Diana in 1997.

According to the former SAS soldier - known as "Soldier N" - a light was shone into Diana's car causing it to crash.

But that theory has been thrown out following a three month-long investigation by Scotland Yard, which enjoyed "unprecedented access" to records held by the special forces. It found no grounds to bring a prosecution.

Assistant commissioner Mark Rowley said: "Whilst there is a possibility that the alleged comments in relation to the SAS's involvement in the death may have been made, there is no credible or relevant evidence to support a theory that such claims had any basis in fact.

"Having reviewed the exercise and its findings, I am satisfied that there is no evidential basis upon which therefore to re-open any criminal homicide investigation or refer the matter back to the coroner.

"In light of this information, I have today also written to the Royal House and Lord Justice Baker informing them of the above and providing a copy of the concluding summary."

Princess Diana
Princess Diana two months before her death (Reuters) Reuters