In August the Met police began an initial probe into the claims, having received material suggesting the elite unit was linked to the car crash in 1997.
In letters to the Queen, Prince Charles and Mohamed Al Fayed, Dodi's father, the police said there was "no credible evidence" to support this theory. Officers said they'd been given "unprecedented access" to special forces records and taken statements.
Former Harrods owner Mohamed was "disappointed but not discouraged" by the outcome, his solicitor Simon McKay said.
He called the scoping exercise "the latest whitewash in a 16-year cover up".
An inquest in 2008 found the death of the Princess and her friend were caused by the negligence of the driver Henri Paul and the distraction caused by paparazzi pursuing the couple from the Ritz in Paris.
This year's Scotland Yard inquiry concluded that the nature of the tragedy meant "there will have been those who, for whatever motivation, will have sought to demonstrate particular inside knowledge, or to claim some form of kudos or recognition".