Mohamed Al Fayed has arrived to give evidence at the inquest into the deaths of Princess Diana and his son, Dodi.
Diana, Princess of Wales, told Mohamed Al Fayed she was pregnant, the Harrods owner said at the inquest into her death and that of his son, Dodi.
The Harrods owner has long maintained the princess and his son were murdered in a conspiracy involving the security services and the Duke of Edinburgh.
The claim came as he began his evidence at the Royal Courts of Justice.
Mr Al Fayed says his son told him in a phone call that he and Diana were soon to announce their engagement.
Mr Al Fayed has long maintained the princess and his son were murdered in a conspiracy involving the security services and the Duke of Edinburgh.
Outside the Royal Courts of Justice, he said: "This is the moment for me to say exactly what I feel happened."
He told the jury: "Diana told me on the telephone that she was pregnant. I am the only person they told."
He added that French intelligence had helped British intelligence services to execute the murder.
The couple died, along with driver Henri Paul, when their car crashed in Paris in 1997.
The couple died, along with driver Henri Paul, when their car crashed in Paris in 1997.
Mr Al Fayed said he had been "fighting for 10 years" and added: "With God's help I hope the truth will come out."
BBC royal correspondent Peter Hunt said that, for four months, the inquest has looked at evidence behind many of Mr Al Fayed's claims.
The tycoon will personally tell the inquest jury of his theories surrounding the crash.
Conspiracy theory
Our correspondent said that at the heart of Mr Al Fayed's case was a belief that a cordial friendship with the Royal Family soured once Diana and Dodi's relationship became public.
Mr Al Fayed claims they could not accept an Egyptian Muslim as stepfather to the future King of England - so a conspiracy, involving MI6 and Prince Philip, was hatched to murder the couple.
The coroner, Lord Justice Scott Baker, has already outlined Mr Al Fayed's allegations to jurors.
He told them: "It's his belief that a decision was taken to kill both Diana and Dodi. He places Prince Philip at the heart of the conspiracy.
"You will have to listen carefully to the witnesses you hear to see whether there is any evidence to support this assertion."
