Rolling Stones frontman Sir Mick Jagger escaped an assassination attempt at the hands of Hells Angels in 1969, a BBC Radio 4 documentary has claimed.
A fan was stabbed to death at the Stones' notorious Altamont concert
A former FBI agent told The FBI at 100 series the gang tried to reach Jagger's home in Long Island, New York, by sea, but a storm almost sank their boat.
He said the singer had become a target in a dispute over security at concerts.
Presenter Tom Mangold said the FBI, who only learned of the plot afterwards, regarded it as a "serious attempt".
It is not clear whether Jagger was informed of the plot and his spokesman declined to comment.
The row with the gang began after the death of a teenage fan at a free gig at Altamont Speedway in California.
The Hells Angels were hired by Jagger to work as security at the concert, but were subsequently fired after the incident.
"They were going to kill him in retribution for his firing their security forces," former FBI agent Mark Young told the documentary.
"Their plan involved making entry onto his Long Island property, going by boat.
"As they gathered the weaponry and their forces to go out on Long Island Sound, a storm rolled up, which nearly sunk the watercraft that they were in, and they escaped with their own lives.
"They never went back and reinstituted the plan."
The programme will be broadcast on 11 March at 1545 GMT.