Princess Diana and Dodi Al Fayed
The bronze fountain memorial to Dodi Al Fayed (R) and Diana, Princess of Wales in Harrods, central London (Reuters)

Nearly 16 years after the death of Princess Diana, a new conspiracy theory has surfaced, claiming British military involvement in the fatal Paris car crash that killed Diana, her boyfriend Dodi Al Fayed, and her driver Henry Paul.

British police deny the military had anything to do with the August 1997 crash.

"This is not a re-investigation," London police said in a brief statement.

According to an article in the Sunday People, the new theory originated when the parents-in-law of a British Special Forces sniper contacted military authorities and then the Metropolitan Police. The soldier has been identified only as Soldier N

The article, which does not quote a source, claims that a seven-page handwritten letter was sent by Soldier N's in-laws. According to the paper, the soldier had once boasted to his now estranged wife that the elite British Special Air Service (SAS) commando unit was responsible for the deaths.

According to the report, the Ministry of Defence, the Royal Military Police and the Service Prosecuting Authority have been aware of the claim since September 2011, when it was sent during the court martial of Soldier N's roommate, Sergeant Danny Nightingale. All references to the SAS were edited out of court documents.

"He (Soldier N) also told her (his wife) that it was the XXX who arranged Princess Diana's death and that has been covered up," a Mirror report said.

The UK's Ministry of Defence told CNN: "This is for the Metropolitan Police to investigate."

Scotland Yard responded: "The Metropolitan Police Service is scoping information that has recently been received in relation to the deaths of Diana, Princess of Wales and Dodi Fayed and assessing its relevance and credibility. The assessment will be carried out by officers from the Specialist Crime and Operations command."

The father of Diana's boyfriend Dodi, Mohamed Al Fayed, has long maintained that the car crash that killed Diana, his son and their driver was a conspiracy that involved the British state.

In 2008, an inquest jury ruled that Diana's driver Henry Paul and the paparazzi following their car were both to blame for deaths of Diana and Dodi Fayed.

The possibility that the couple were murdered was ruled out due to a lack of evidence.