Arnold Schwarzenegger says the fling with his housekeeper that produced a baby and later ended his marriage was the "stupidest" thing he ever did.

In excerpts from a television interview to air Sunday, a day before his memoirs are published, the former California governor admitted he "inflicted tremendous pain" on his wife Maria Shriver, a member of the Kennedy political dynasty.

"She gave up her television career for you," CBS television's "60 Minutes" journalist Lesley Stahl recalled, referring to Shriver's previous career. "I mean, wow! Was this just the most unbelievable act of betrayal to Maria?"

Schwarzenegger responded: "I think it was the stupidest thing I've done in the whole relationship. It was terrible. I inflicted tremendous pain on Maria and unbelievable pain on the kids."

Shriver filed for divorce in July last year citing "irreconcilable differences" with her husband, whom she met in 1977 and married in 1986, following him into the California governor's mansion in 2003.

Schwarzenegger had admitted in May 2011 that he had fathered a child, called Joseph and born in 1997, with the family's long-time housekeeper, Mildred Baena, and announced the couple's separation.

The former bodybuilder and Hollywood movie star said Shriver had not read the book.

"She knows that it's about my whole life and that I would not write a book and kind of leave out that part and make people feel like, 'Well, wait a minute. Are we just getting a book about his success stories and not talk about his failures?'

"I wanted to write a book about me," he said of the memoirs, called "Total Recall" -- after the 1990 blockbuster in which he starred -- and due to be published on Monday.

In the book, subtitled "My Unbelievably True Life," Schwarzenegger also writes about another affair he had outside of his relationship with Shriver, according to CBS.

Allegations of sexual misconduct and affairs have long dogged the Austrian-born actor turned politician, who returned to the big screen in "The Expendables 2" this year, and has a number of other movies due for release.

[Image via Agence France-Presse]