An official investigation into the death of British Olympic gold medal-winning sailor Andrew Simpson will be carried out.

America's Cup chiefs, local law enforcement and the US Coast Guard have launched a probe to establish how the 36-year-old became trapped beneath his 72ft Artemis catamaran when it capsized in a training accident in San Francisco.

All 10 of Simpson's crewmen were found after the vessel overturned, but the athlete was not discovered in time, and rescuers were unable to resuscitate him.

"These guys are the best, Andrew was the best, top of his game, that means they push, they push hard, second is not good enough," Stephen Barclay, chief executive of the America's Cup Event Authority, told reporters.

"In any sport there are incidents when people push themselves and their apparatus to the limits.

"In this case it ended with a fatality and we need to find out why."

Simpson won a gold medal in the Star class at the 2008 Beijing Games before earning a silver medal in the same category at London 2012.