Schwarzenegger admits he had an affair (and a son) with his househelp

Schwarzenegger and wife

Arnold Schwarzenegger has spoken for the first time about fathering a love child with his housekeeper, describing how his wife confronted him in a marriage counselling session the day after he left office as Governor of California

In an autobiography to be published next month Mr Schwarzenegger says he "wanted" for years to believe that the boy, who was born in 1997, was not his.

But as he grew up the physical resemblance became so strong "I realised there was little doubt that he was my son."

Mr Schwarzenegger and his wife Maria Shriver, a niece of President John F Kennedy, separated last year after he confirmed he had fathered the boy, Joseph, with their Guatemalan-born housekeeper Mildred Baena.

A copy of the actor and politician's much anticipated book, "Total Recall: My Unbelievably True Life Story," the details of which have been closely guarded, was obtained by the New York Daily News.

According to the newspaper it details how Mr Schwarzenegger went to a couple's counselling session on January 4, 2011, the day after his term as Governor expired, thinking it was to help him and his wife, with whom he has four children, make the change from public to private life.

He wrote: "The minute we sat down, the therapist turned to me and said 'Maria wanted to come here today and to ask about a child – whether you fathered a child with your housekeeper Mildred.' I told the therapist 'It's true'."

He then told his wife: "It was my screw-up."

Mr Schwarzenegger wrote that he should have told his wife the secret a long time ago but "instead of doing the right thing I'd just put the truth in a mental compartment and locked it up where I didn't deal with it every day."

According to the newspaper the former Mr Universe recounts in the book that his illegitimate son was conceived in the guesthouse of his California mansion while his wife was on holiday.

At the time he was making the film "Batman & Robin," in which he starred as Mr Freeze.

He blamed his own arrogance in believing "you'll get way with ignoring the rules" for what happened.

After realizing the boy was his he kept the housekeeper in her job to "control the situation," the newspaper reported. Miss Shriver did ask him about the parentage of the child years ago but he denied it at that time.

While he was Governor the housekeeper's husband left her and Mr Schwarzenegger began financially supporting her and the child.

He reportedly reasoned that this was politically acceptable because he had not campaigned on family values.

Mr Schwarzenegger wrote: "I blocked out the fact that as a husband and father, as a man with a family and wife, I was letting people down."

His explanation of the scandal comes at the end of a 624-page tome which covers his journey from Austria to the United States and his achievements in bodybuilding, Hollywood and politics.

It is unclear whether Miss Shriver, with whom his divorce is not yet finalised, was given details of the book in advance.

The book, which is published on Oct 1, is part of an effort to rehabilitate Mr Schwarzenegger's image.