The Underbelly actor, who recently quit his presenting job on The X Factor after allegedly attacking girlfriend Rachael Taylor at a hotel in Rome, has reportedly always had issues with his "temper".
Australian television star Bert told A Current Affair that his son's life is a "train wreck". He 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. We should have seen the signs... but we didn't."
Wife Patti added: "There was a bomb about to go off somewhere, sometime... it's a mental health issue. He's always had a bit of a problem with his temper, even as a kid, but I do think it's accelerated. We don't know how to handle it."
They also confirmed that Matthew had proposed to Taylor shortly before the alleged assault.