A French fishing trawler that sank 14 miles south-west off Lizard Point was not pulled under the waves by a British submarine, according to a French judge.

The 72ft Bugaled Breizh, which means "child of Brittany" in Breton, sank in January 2004, and there have long been suspicions in France that Royal Navy submarine HMS Turbulent.

The sinking, a day before a large NATO exercise, claimed the lives of all five crew members, with the families believing that a submarine had dragged the vessel down after becoming entangled in its fishing gear.

However French judge, Brigette Lamy, has now said she agreed with what the Royal Navy has always insisted, that HMS Turbulent was “definitely in port” at Devonport Naval Base at the time.

Judge Lamy was investigating whether charges could be brought against HMS Turbulent or its crew.