AceShowbiz - Actor Matthew Newton has been placed on suicide watch in rehab. The "Underbelly: A Tale of Two Cities" star is currently undergoing treatment in Sydney for the second time this year following an alleged bust-up with his girlfriend, "Transformers" star Rachael Taylor.

A day after he was admitted to the facility, the actress took out an apprehended violence order against the star, alleging she was the victim of two "gravely serious" attacks by Newton while they were vacationing together. Newton's parents, Bert and Patti, opened up about their fears for their son on Monday's August 30 edition of Australian news show A Current Affair - and revealed their son is under observation from experts who fear he may take his own life.

When asked if he has threatened to kill himself, Patti said, "Many times". She explained, "He's the saddest I've ever heard anyone sound. He's just so sad. He knows what's happened. He knows what he's done. Hopefully, medication will help him sort it out and work out why he needs all this medical help. All Bert and I can do is be very sorry for everything that he has done to cause any hassle with anybody."

Patti also revealed she warned Taylor to be "careful" in the relationship because of Newton's behavior. She adds, "I told her many times that she had to be really careful and I worried about her, and I told her... a long time ago that: 'You have to be careful. He needs help. He needs medication'. And that's no excuse for what he did. I think we were all aware there was a bomb about to go off somewhere, sometime."

Newton's mother admits she has spoken with the actress since the incident that led to the split and the AVO order: "I don't think we have to say anything to Rachael. Rachael spoke to me the night she was leaving (Matthew) and she said he's very sick - very, very sick, he needs psychiatric help, and I said, 'I know, I agree'."