Olivia Newton-John admitted she was never able to "find peace" after her on-off boyfriend vanished at sea

Cameraman McDermott, with whom Olivia had an on-off romance for nine years following her divorce from Matt Lattanzi in 1995, disappeared while on an overnight fishing trip on June 30, 2005.

He set sail off the coast of Los Angeles with 22 others, but no one noticed when the boat 'Freedom' returned without him.

It was several days until anyone spotted McDermott was missing when he failed to turn up to a family gathering on July 6 and when police were called five days later investigators were faced with a mystery.

Some of his personal belongings including his keys and passport were discovered on the boat, and his car was found parked near the marina.

Almost a year after he vanished, the Coast Guard Investigative Service probe was closed and "did not find any evidence of criminal action, suicide, accident or hoax" - concluding he was probably lost at sea.

Unsubstantiated rumours have been circulating he faked his death and hid in Mexico to avoid a mountain of debt.

He had been briefly married and had a son, and a court had ordered him to pay $8,000 (£6,600) in backdated child support.

The 48-year-old then filed for bankruptcy with debts of more than

$30,000 (£25,000).

Olivia - who went on to marry film producer John Easterling in 2008 - admitted she was never able to get over his disappearance as she lacked closure.

She told Australian Women's Weekly magazine: "I don't think I will ever really be at peace with it.

"I think there will always be a question mark."

Olivia added in a chat in 2016 she had "let go" of the incidence but still wondered what happened to her ex.

She said: "It's human to wonder. Because whenever you go through difficult times, there's always those concerns.

"Those are the things in life you have to accept and let go. Of course questions always come up and that's human. But you know, I live on."