Michael Douglas has blamed a cancerous tumour which developed in his throat three years ago on his sex life.

In an interview in the Guardian, the 68-year-old said the cancer was caused by a sexually transmitted disease.

"Without wanting to get too specific, this particular cancer is caused by HPV (human papillomavirus)," he said.

"I did worry if the stress caused by my son's incarceration didn't help trigger it. But it's a sexually transmitted disease that causes cancer."

Read Newsbeat's guide to HPV

The two-time Oscar winner revealed in 2010 that he was battling with stage-four cancer, but beat the disease thanks to chemotherapy and radiotherapy.

His son Cameron, 34, is serving a 10-year prison sentence for drug possession and dealing.

"I have to check in regularly, now it's every six months, but I'm more than two years clear," he said.

"And with this kind of cancer, 95% of the time it doesn't come back."

In the interview, Michael Douglas also claimed that oral sex was also the cure for his cancer, a comment which has been disputed by doctors.

Research studies from Malmo University's Faculty of Odontology and in The New England Journal of Medicine both suggest a correlation between oral sex and throat cancer.

HPV infection is also the cause of 99% of cases of cervical cancer, according to studies cited by the NHS.

Douglas' wife, Oscar-winner Catherine Zeta-Jones, had further treatment for bipolar disorder in April.

The Welsh actress, 43, won an Academy Award in 2003 for her supporting role in Chicago and has appeared in films including Traffic and Ocean's Twelve.

Michael Douglas promoted his latest role, as flamboyant entertainer Liberace in Behind The Candelabra, at the Cannes Film Festival last month.

Follow @BBCNewsbeat on Twitter