Speaking on Nine's A Current Affair in an interview to air tonight, she says his biggest problem is not drugs or alcohol, it’s his mental health.

She says in the days leading up to her son's reported attack on girlfriend Rachel Taylor in Rome, he was calling her from all over the world, told her he'd proposed and then everything went sour.

Australian television legend Bert Newton told the program his son's life had become "a bit of a train wreck" and that he and Patti Newton "should have seen the signs ... but we didn’t".

"A lot of things that have unfolded in recent times, the great majority of those things we’ve learned about them through the media," Bert Newton said.

"People might have had the impression that whatever happened, and whatever was done, we condoned it, and when a situation like this comes along, you don't.

"A lot of people don’t have the experience, but when it concerns your child you say 'well, of course we love him and we support him'.

"I think I made an error in saying that because I do love him and I do support him, but I don't support or condone any of the things that have happened."

Matthew Newton lost his job as host of Seven's The X Factor last week and was admitted to a psychiatric facility.

Ms Taylor accused him of two "unprovoked violent assaults" and has applied for an AVO against him.

His manager Titus Day quit after the allegations emerged.

smh.com.au and AAP