The letters, sent while he was serving in the Gulf War between December 1990 and June 1991, were allegedly taken from his Devon home last March.

Diana: "Yes, I adored him. But I was very let down"

Mr Hewitt, 40, said the handwritten letters were stolen by a girlfriend. They ended up in the possession of Lawrence Graham, the London law firm acting for the late princess's estate.

A writ was issued last December against the law firm by Mr Hewitt.

Harkavys, Mr Hewitt's lawyers, said on Wednesday: "The proceedings initiated by the High Court writ have been satisfactorily concluded between the parties.

"All 64 letters written by the late Princess Diana have today been returned to Mr. Hewitt."

Michael Coleman, senior partner of Harkavys, added: "Mr Hewitt has no desire or intention of publishing the letters."

A spokesman for Lawrence Graham declined to comment.

Mr Hewitt's former fianc�e, model Anna Staiano Ferretti, was arrested in April 1998 after The Mirror newspaper said she tried to sell the letters to the tabloid for �150,000 pounds.

Letters kept safe

The Mirror handed the letters over to Diana's private office at Kensington Palace, without publishing them.

Police later said Ms Ferretti would not be prosecuted.

The princess's mother, Frances Shand Kydd, said she and the other executors of her daughter's will would be happy to hand the letters back, provided Mr Hewitt guaranteed their "safe-keeping."

After Mr Hewitt co-operated in a 1994 book about the affair, Princess in Love, Diana acknowledged the relationship but said she was hurt by Mr Hewitt's involvement.

In her television interview on BBC's Panorama in 1995 the princess confessed to her relationship with Mr Hewitt, saying: "Yes, I adored him. Yes I was in love with him. But I was very let down."

Possible prosecution

No one currently faces any criminal charges in connection with the alleged burglary, but Mr Coleman said on Wednesday that lawyers acting for Mr Hewitt were considering the possibility of a private prosecution.

Diana was killed in a car crash in Paris with her friend Dodi al-Fayed in August 1997.