An investigation is under way into how a yacht capsized off the south Devon coast, leading to the death of one of the crew.
A man in his 20's died and four other crew members were rescued from a life raft after the Hooligan Five sank on Saturday at Prawle Point near Salcombe.
The Marine Accident Investigation Branch will look into reports that the boat capsized after losing its keel.
Attempts to recover the yacht have failed, but it may still be salvaged.
Torbay lifeboat tried to tow the wreck of the yacht to port when it broke free. It is semi-submerged and is expected to sink.
Brixham coastguards said they would be keeping a watchful eye on the vessel in the interests of safety.
An air and sea rescue operation was launched on Saturday morning after a merchant ship spotted a distress flare.
Two RNLI lifeboats, Sea King rescue helicopters, Royal Fleet Auxiliary vessels Wave Knight and Wave Ruler, and HMS Portland were involved in the rescue of crew from the Solent-registered yacht.
Four people were airlifted to hospital in Plymouth suffering from slight hypothermia. They are said to be recovering well.
Salcombe lifeboat found the body of the missing crew member in the water.
Peter Hodges, of Salcombe Lifeboat, said the keel had separated from the boat.
He said: "Either the keel must have struck an underwater obstruction or else there would have been a fault with the boat and the attachment of the keel to the boat. One of those two things must have happened."
A Department of Transport spokeswoman confirmed the Marine Accident Investigation Branch had sent a team to Devon to conduct a preliminary examination of the incident.