Olivia Newton-John says it’s only human to wonder what happened to her ex-partner Patrick McDermott, who has reportedly been seen alive after disappearing in 2005.

The Grease star and McDermott had been dating for nine years when he disappeared off a fishing boat in California.

Newton-John told the Nine Network’s 60 Minutes program the aftermath of his disappearance was a tough time.

“Yeah it was very hard. He was lost at sea and nobody really knows what happened,” Newton-John told Nine.

Reports from 2009 and 2016 claimed McDermott was still alive and living in Mexico.

When asked if she wondered whether McDermott was still alive, Newton-John said: “Of course.”

“I mean it’s human to wonder. But you know … those are the things in life you have to accept and let go,” she said.

“Because whenever you go through difficult times there’s always those concerns. But you know, I live on, and of course questions come up, that’s human.”

.@Olivianj has never really talked about the controversy over her former boyfriend Patrick McDermott, who went missing in 2005. #60Mins pic.twitter.com/Ss6eLHTpOr

— 60 Minutes Australia (@60Mins) September 25, 2016