Actress Kathleen Turner has responded after fellow star Michael Douglas revealed the pair had a secret dalliance during filming for their 1984 hit Romancing The Stone.

Douglas, 82, revealed how he and Turner, now 72, fell for each other while he was separated from then-wife Diandra Douglas.

“The chemistry I had with Kathleen Turner was so strong, audiences have been certain for years that we were in a relationship together while making the film,” Douglas wrote in an extract from his memoir One Helluva Ride, shared by People magazine at the weekend.

“We both denied it through Romancing The Stone, Jewel of the Nile, War of the Roses, and even while doing press a few years ago for The Kominsky Method.

“The official story went as follows: Yes, we confessed, we had amazing chemistry. Yes, we were both, as Kathleen said, ‘terrible flirts’, and yes, we were both tempted, but nothing ever happened between us.

“That was a lie.”

Douglas said the lie was “meant to protect my wife and son”, and he and Turner had “told the world for 40 years”.

“Kathleen and I never hit a rough spot. We found each other first as friends, then as co-stars, and finally as lovers,” he said.

“Following an exhausting day of shooting in the jungle [in Mexico], we’d go out and have a meal, or head out with the group and afterward I would sneak into her hotel room after everybody was asleep.

“There were no cameras in elevators, no assistants using cell phones to take pictures.”

Neither the film’s director Robert Zemeckis nor Douglas’s costar Danny DeVito were aware of what was happening between the two stars, Douglas says.

Douglas and Turner also started together in 1989’s War of the Roses. Photo: AAP

The relationship ended after Douglas’s then-estranged wife Diandra Luker brought their son Cameron for a visit to Mexico. Douglas says Luker suspected something between him and Turner.

But Turner “didn’t want to interfere”, he writes, and Douglas ultimately went back to his marriage for the sake of his son.

“After that visit, Kathleen and I ended things, and I went back to Diandra. I did it for Cameron, but we shouldn’t have gotten back together,” he writes.

“After that first split it was never the same between us ever again.”

Douglas and Luker finalised their divorce in 2000 and he married fellow actor Catherine Zeta Jones later that same year.

At the time, Turner was married to real estate developer Jay Weiss. They share a daughter, 38-year-old actress Rachel Ann Weiss.

Turner and Weiss divorced in 2007 and she has not remarried.

At the weekend, she acknowledged the affair with Douglas in a brief statement.

“Good heavens what a fuss about something 40 years ago!” she said.

“I love Michael and I look forward to enjoying the book.”

Turner said she kept up the public story with Douglas as she had “hope for” something romantic between them at one point.

“I was yearning, but he was still married to [Luker] … although they were separated, and so I thought there was hope for me,” she told Closer magazine.

Douglas’s book includes a note that he asked Turner for permission to include their story.

-with AAP