I thought mum would come back. She didn't, reveals Hugh Jackman

Fame sits easily on Hugh Jackman's broad shoulders. For an Oscar-nominated multimillionaire, he comes across as surprisingly well-balanced. This, he says, is all down to his wife.

"Debs has strength and a lot of courage," says Jackman, sitting in an hotel in the midst of the Toronto Film Festival, his impressive muscles subtly disguised beneath a sombre suit. "She is very grounded. Our family matters more than anything - and I mean anything. At the Oscars [which he hosted in 2009], when I put my hand on my heart, that's a sign to Debs out there, a reminder that this is what matters and that all the rest - the awards and the money and the fame - may come and go. There'll be times when I'm flavour of the month, times when I'm not. But Debs and my kids are what matters to me."

The Antipodean couple, now based in New York, met in 1995 while starring together on the Australian television show Corelli, and despite the 13-year age gap - he is 44, she is 57 - Jackman proposed within four months.

"It was the best decision I ever made. It helps, too, that we have made a pact that we will never spend more than two weeks apart, and for me, when I'm working, it's a deal- breaker. When you look around and see the marriages in this business that don't survive, it is mostly because people grow apart because they spend too much time away from each other. Debs and I have always been determined that won't happen to us." Jackman's attitude to marriage is coloured by his parents, who separated when he was seven. Christopher and Grace were Brits who went to Australia as "10 Poms pounds".

They had five children - Hugh was the youngest - but when the marriage broke down, his mother returned to England. "My mum's departure was a big, defining moment for me. It was terrible. I couldn't quite understand it, and I kept thinking that she'd come back. But she never did." For all that, Jackman has stayed in touch with her and they are on good terms. "She comes to visit us, and when I'm in England, I go to visit her, and we've always had a good relationship.

"I know a lot of people would assume I'd be angry with my mum, but it's never really felt like that. We've had many chats about what happened and exorcised our demons. She's very open, and I've always found it easy to talk to her so it hasn't been something that has forced me into therapy. I think on some level I understand, particularly as an adult now, what she did and why it happened." He is devoted to his own family, and takes his inspiration from his father. "After my mum left, my dad was unbelievable, and I never saw him crack. I also never heard him say a bad word about anyone, including my mum. I still look up to him tremendously, and I guess that being brought up by him has informed who I am and what I aspire to be. I feel that if there are strengths and qualities of my personality, I get them all from him. For me, he's always been a kind of rock."

Jackman's children, Oscar, 13, and Ava, 8, were adopted after the couple discovered that they couldn't have children naturally. Jackman has described his road to parenthood as "painful … trying to have children is wonderful, and when you feel as though that's not going to happen, there's a certain anxiety.

"We'd always planned and hoped to have both adopted children and biological children. But it turned out we didn't have biological children." His children were very much on his mind during shooting of his new film, Prisoners. It tells the story of two ordinary families, the Dovers and the Birches, whose daughters slip out from a Thanksgiving dinner and fail to return.

Jackson's character, Keller Dover, becomes convinced that a troubled loner has abducted them, and when police fail to charge him, he takes the law into his own hands. The film is a disturbing reflection of news stories that seem now almost everyday occurrences, reminding British audiences, no doubt, of cases such as the Soham murders or April Jones. As Jackman researched the role, "the hours I spent looking into this subject were the most soul-destroying of my life. What are the steps that people take when their child goes missing? What happens on day one? Do they hand out leaflets? Do they knock on doors themselves? What happens to relationships? It left me with an overriding sense of responsibility towards people who have actually experienced this nightmare, and right now it seems to be happening to far too many people". He admits that playing Dover has changed him.

"My character says, 'Pray for the best but prepare for the worst', whereas I have always been an optimistic kind of guy who doesn't expect any trouble. Since Prisoners, though, I feel I have lost some of that naivety. The world is not always pretty, and you do need to prepare your kids to make sure that in certain situations they'd know what to do. So did I hug my kids a bit tighter when I came home from filming? Well, yes I did." Jackman's career, which has included star turns in Baz Luhrmann's Australia and Woody Allen's Scoop, a Tony-winning performance in the Broadway show, The Boy from Oz, and a Best Oscar nomination for Les Miserables, has been on an upward trajectory since he was cast, six-pack and all, as Wolverine in 2000. He has just reprised the role in a new X-Men film, Days of Future Past, due for release next year. In the early days, he says, he was not comfortable with either the fame or the money.

"At the start, the money side of things didn't sit too easily with me. I never went into acting for the money, and it seems like an obscene amount gets thrown at you for doing the thing that you love. I don't think, either, that money has made me any more happy than I was when I was earning 375 pounds a week in [Trevor Nunn's] Oklahoma! at the National. Debs and I had a great time then, and we have a great time now. "Yes, I like the fact that I can get my clothes dry-cleaned, that I can go into a restaurant and not choose my food and wine according to the prices on the menu. But the truth is that I'm not materialistic, and neither are my parents or my siblings."

But he likes to spread the wealth around. When he's on a set, he buys lottery scratch cards for the crew. "It's usually about 250 a week and it's just a bit of fun. And, by the way, if you want to get rich, don't buy scratch cards. I think I've done it for 12 years and the biggest prize anyone has won is 50 quid on Les Mis." Although Jackman is a proud Aussie - "I'm never happier than when we're winning the Ashes" - he has inherited an English sensibility, too. "There were no elbows on the table, and manners really mattered. Plus, I always feel at home whenever I work in England. It doesn't feel strange to me at all." His father is a frequent visitor to sets his son is working on - and seems particularly at home if they are in England, as Les Mis was. "When he was there, he'd sit reading the Telegraph and doing the crossword."

Prisoners is out on September 27