"It was discussed that oral sex is a suspected cause of certain oral cancers as doctors in the article point out but he did not say it was the specific cause of his personal cancer," People magazine reported the unidentified spokesman said in a statement.
Douglas, 68, had a cancerous tumor on the base of his tongue treated through radiation and chemotherapy and said two years ago the cancer was gone.
In a weekend interview with a British newspaper, The Guardian, Douglas was asked if he regretted drinking and smoking since they can cause oral cancers.
"No. Because without wanting to get too specific, this particular cancer is caused by HPV [human papillomavirus], which actually comes about from cunnilingus," he can be heard saying in an audio recording posted on The Guardian's website.
The newspaper also quoted him as saying: "I did worry if the stress caused by my son's incarceration didn't help trigger it. But yeah, it's a sexually transmitted disease that causes cancer."
The magazine noted HPV can play a role in a certain type of oral cancer that attacks parts of the tongue, palate, throat walls and the tonsils. But experts say the clarification was in order.
"Oral sex doesn't cause oral cancer," Dr. Maura Gillison, a head and neck medical oncologist and professor at Ohio State Comprehensive Cancer Center, told People. "It's a means by which to acquire an infection that rarely causes cancer."
Douglas' son Cameron pleaded guilty in 2011 to possessing drugs while in federal prison for drug dealing.