( CNN ) -- There is `` no credible evidence '' to support a claim that the British military was involved in the deaths of Princess Diana , her boyfriend and their driver , according to London 's Metropolitan Police . The allegation first surfaced in August , roughly 16 years after the woman who would now be a royal grandmother died in a Paris car crash . Officers were tasked with looking into whether there was any truth to it . `` Every reasonable line of enquiry was objectively pursued in order to fully evaluate any potential evidence , '' police said in a statement released overnight Monday . `` The final conclusion is that whilst there is a possibility the alleged comments in relation to the SAS 's involvement in the deaths may have been made , there is no credible evidence to support a theory that such claims had any basis in fact . '' SAS is short for Britain 's elite Special Air Service . Wildly popular in life and death , Diana died on August 31 , 1997 , after the car she was riding in slammed into a pillar in a Paris overpass . Her boyfriend , Dodi Fayed , and their driver , Henri Paul , also died . Investigators concluded that Paul was drunk and speeding when the accident occurred , and despite at least three inquiries -- including a lengthy London police inquiry that poured cold water on all forms of conspiracy theories in Diana 's death -- whispers of collusion and cover-up have persisted . Rare photo of teenage Diana sold . The latest claim , published by Press Association , the Sunday People newspaper and other British media outlets , alleged that members of Britain 's elite SAS commando unit were involved in assassinating Diana . The claim appears to have been sent first to military authorities and then to London police by the parents-in-law of a British special forces sniper after his marriage had fallen apart , according to an article on the website of the Sunday People newspaper . It did not offer a source for its reporting , but the paper indicated that the parents were questioning the integrity of the soldier , who had testified in another soldier 's court-martial . Sunday People said it had seen a seven-page handwritten letter by the in-laws alleging that the soldier , whom the newspaper did not name , had boasted to his wife that the commando unit was behind the deaths . Neither the Sunday People piece nor an earlier version carried by Press Association offered details of the claimed involvement by soldiers in the deaths . The princess left behind her two children , Prince William , whose wife recently gave birth to Diana 's first grandchild , and Prince Harry . Some 2.5 billion people around the world watched Diana 's funeral . Princess Diana 's favorite fairytale dress could be yours . CNN 's Michael Pearson , Atika Shubert and Erin McLaughlin contributed to this report .
Claim alleges British military was involved in Princess Diana 's death . There is `` no credible evidence '' to support such an allegation , say police . Diana died alongside her boyfriend and their driver in a Paris car crash .