NAZI leader Rudolf Hess flew to Scotland in search of the Holy Grail, a Scots conference will hear this weekend.

Mystery surrounds the mission of Hess, whose plane was shot down over Scotland during the Second World War.

But on the 58th anniversary of his capture author Nigel Graddon will tell a meeting of the Sauniere Society he was here on a mission to capture the prized relic for Hitler.

The South African author has been invited to talk to the writers' society about his beliefs.

He claims Hess flew to Scotland on May 10, 1941, after being told by SS officer Otto Rahn the Grail could be in Rosslyn Chapel.

Rumours of a secret vault in the chapel, in Midlothian, are well documented and the Knights Templar, whose ancestors are buried in the vault, believe it holds many secrets including the Holy Grail and the head of John the Baptist.

It has always been claimed Hess was heading to Scotland on a peace mission.

But at a Sauniere Society symposium at the Templar Lodge Hotel in Gullane, Midlothian, tomorrow Mr Graddon will put forward his theory about the secret agenda behind Hess's trip.

He believes it was part of a number of missions ordered by Hitler to hunt down the cup of eternal life.

Tales of Hitler's obsession with the Holy Grail have been widely documented and even inspired the Hollywood movie Indiana Jones and the Last Crusade, starring Sean Connery.

During the war it was believed Himmler set up a top level occult group and it was believed German High Command decisions were influenced by advice given by Hitler's personal Japanese astrologer.

Mr Graddon's theory is based on reports Hitler sent a battalion to Montsegur about 30km from Rennes-le-Chateau to excavate for the Grail.

The SS officers, who included archaeologists, hunted until they found treasure, but no Grail.

Following this it is believed a second operation was planned, this time focusing on Rossyln Chapel and Hess was sent ahead to investigate, but he was captured and made a prisoner of war.

Mr Graddon said: ''This is a true story, although not an easy one to prove.

''Rudolf Hess, deputy Reichfuhrer, flew to Scotland following information supplied to him by Otto Rahn regarding the location of the Holy Grail at Rosslyn Chapel.

''After confirmation the Holy Grail was not after all at Montsegur, it was concluded the most likely alternative place was at Rosslyn Chapel.''

Mr Graddon believes his theory will be backed up in secret MI5 files.