Robin Cook's move came amid growing speculation over the death of Alan MacLean on a yacht skippered by a Frenchman.

BBC Scotland's Colin Wight reports

The announcement came after the captain, Phillippe Sorel, had telephoned Mr MacLean's family to plead his innocence after they cast doubt over his version of events.

The 28-year-old was reported by Mr Sorel to have been shot by pirates off the coast of Somalia on 11 September, but the dead man's family - who live in Aberdeen - have questioned the story.

Mr Cook has issued a formal request to the French Government to launch an investigation into the death.

Robin Cook: Seeking French inquiry

If the French authorities agree, the investigation will be carried out by a magistrate in Montpelier.

The news has been welcomed by Mr MacLean's family in Aberdeen.

Mr Sorel said Mr MacLean had been killed by pirates after trying to defend himself with a didgeridoo.

But Mr MacLean's father, Neil, said his comments raised more questions about his son's death than they answered.

'Pirates killed him'

"I did not murder my Scottish friend. Pirates killed him," Mr Sorel, 41, told the Glasgow-based Daily Record newspaper.

Mr Sorel said that after their yacht the Correlation had been boarded by gun-wielding pirates in the Indian Ocean, he and the other crew members had locked themselves in the hold.

"After a few minutes Alan said they were shooting blanks,'' Mr Sorel told the newspaper. ''He had a didgeridoo on board and suddenly he went in his cabin and took this and ran out shouting.

"Then I heard one man shooting and another man falling."

Mr MacLean's parents are sceptical

Mr Sorel said he buried Mr MacLean at sea because of the intense heat.

He reported the attack to the British Consul General last Thursday in Aden, five days after the killing.

Mr MacLean's 59-year-old father said: "We are extremely pleased to have this news from the Foreign Secretary and hope that the French authorities will carry out an urgent investigation into the death of our son so that all of the questions which I and others have raised can be fully answered."

Mr MacLean also thanked the media for raising the profile of the case.

He said: "Since we were notified of the loss of our son we have been motivated to ensure that the authorities took all steps to find the truth concerning his death.

"We are pleased that the British Government is supporting us. My wife and I have been totally occupied with this cause and as a result we have not had the opportunity to grieve and to come to terms with the loss of our son."

The family has received personal reassurances and support from Aberdeen Central MP Frank Doran.

He said he was pleased the British Government had acted swiftly in what was an extremely concerning situation.