Arnold Schwarzenegger has finally spoken out about fathering a love child and splitting from wife Maria Shriver in a revealing new interview with radio shock jock Howard Stern.

The Terminator star described his 2011 separation from Shriver as the biggest failure of his life “without any doubt”.

“Not only failure, but you feel like, ‘I’m to blame for it. It was me that screwed up. And you can’t point the finger at anyone else,'” he told Stern on Wednesday.

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The former governor of California also said he regretted going to therapy with Shriver, describing his marriage counsellor as “so full of s**t”.

“It was the biggest mistake I’ve ever made because that guy was so full of s**t. He said more crap and more nonsense.

“It was absolutely, totally counterproductive to our future relationship or to any hope to get together or anything like that. It was just nonsense talk. It was the biggest mistake. Maria talked me into it. I apologized to Maria. I apologized to the kids.”

Schwarzenegger and Shriver, who are yet to finalise their divorce, have four children together: Patrick, 21, Christopher, 17, Katherine, 25, and Christina, 23.

In 2011, the 67-year-old action star also admitted to fathering a fifth child with his former housekeeper Mildred Baena, 17-year-old Joseph.

“It is fantastic,”Schwarzenegger said of his family, “including my fifth child with Mildred.”

Schwarzenegger described Joseph as “terrific”.

“[H]e totally understands the situation. So, it all has worked out … It’s a very tough situation for him,” Schwarzenegger said.

“It’s a very tough situation for my kids, very tough situation for my family. It was tough for everybody. But it has happened and now we have to figure it out, right?”