Diana inquest to finally start on October 2

Princess Diana: She hoped the lives of her sons would be as normal as possible

A jury will decide the reasons for the crash that cost her and her lover Dodi Al Fayed their lives when their car crashed in a Paris underpass.

Many of the witnesses will give evidence by video link from Paris.

Lord Justice Scott Baker, the fourth coroner to take charge of the proceedings, said the inquest must take no longer than six months.

Princes William and Harry, who said on Wednesday they will always be plagued by doubts about what happened, are known to want a swift conclusion.

The hearing will examine claims by Harrods boss Mohamed Al Fayed, the father of Dodi, that Diana was pregnant by his son and they were murdered in a conspiracy involving MI6 and masterminded by Prince Philip.

But the £3.6million British police inquiry into the crash on August 31, 1997, concluded it was simply "a tragic accident" and that chauffeur Henri Paul, who also died, was drunk.

A key part of the evidence will centre on toxicology tests on Mr Paul, which said he was twice over the drink-drive limit. His parents and Mr Al Fayed insist they are inaccurate.