OLYMPIC star Sir Chris Hoy has admitted he is still a "little bit in shock" after his baby son Callum was born 11 weeks early.

Last month's arrival clearly caught the most successful British Olympic athlete of all time off guard.

However, Sir Chris said yesterday he was delighted the little boy, who was born at 29 weeks on October 15, is making good progress in hospital. Sir Chris and his wife Sarra have been travelling to see their pride and joy in hospital.

The 38-year-old, who retired from cycling after the 2012 London Olympics said: "We weren't expecting Callum until nearer Christmas and he's doing really well considering how premature he was.

"He's growing rapidly, getting stronger, fitter, healthier. It's great fun just going to the hospital and getting to hold him and see him. It'll be nice when we get him home."

Edinburgh-born Sir Chris, who won six gold medals, said yesterday he was still unsure when Callum will get to leave hospital

But the couple are hopeful it will be around his due date, which was close to Christmas.

Sir Chris was speaking after being named Scotland's national treasure along with the Falkirk sculptures The Kelpies for the 20th anniversary of the National Lottery yesterday. He said: "If we could get him back for Christmas that would be an amazing present - but at the moment we're just trying not to think too far ahead."

He also spoke warmly of becoming a father for the first time.

"There's nothing like that moment when you hold your baby for the first time," he said. "It's a pretty stressful situation for it to happen in, but you're just trying to appreciate that moment. We didn't know if it was going to be a boy or a girl. Just finding out is incredible.

"It's a wonderful feeling when you hold your baby boy in your arms."

Sir Chris had announced the birth by putting an image of his newborn boy on Twitter.

He and The Kelpies were chosen by the Scottish public in a poll to mark the Lottery's 20th year.