Arnold Schwarzenegger is set to release his memoirs next year.

The 'Terminator' actor is penning an autobiography that could include details of his recent break-up with Maria Shriver - which occurred earlier this year after she discovered he had a 13-year-old child with their housekeeper Mildred Patty Baena - as well as his career as a bodybuilder and his former role as the governor of California.

His spokesman Adam Mendelsohn explained the 64-year-old star has been working on the project for more than a year but he was reluctant to release it when he was a politician.

He told People magazine: "He has been keeping notes and working on the book for over a year.

"He didn't want to write his autobiography while he was governor."

'Total Recall: My Unbelievably True Life Story' is set to be completed between filming scenes in 'The Expendables 2', which will see him star alongside Sylvester Stallone.

But a source added the book "will not be a tell-all".