Oliver Conway

But as the days pass with no word of her whereabouts, any hope of an emotional homecoming is giving way to a growing sense of dread.

And it is never too late to do the right thing.

Savannah Guthrie ending that report by David Willis.

Curling is normally considered a genteel sport, but it's been rocked during these Winter Olympics by allegations that the Canadians who are in the running to win gold have been cheating by touching the stone when they're not allowed to.

Canadians back home are shocked.

Yeah, as Canadians,

Well, Canada's curling team denies the accusations, but it's not the first Olympics where questions of fair play have been raised.

So why do some athletes cheat?

Professor Steve Peters is a consultant psychiatrist and author of The Chimp Paradox.

I'd like to emphasise that for the vast number of athletes taking part, we highlight the small, very small minority who do cheat.

So if you look at the research that's done on it, it boils down to whether people have integrity and morals.

And if you've got somebody who hasn't got that, then if they're able to cheat and get away with it, they will.

If those who have morals, then they regulate themselves.

So what if you don't have integrity and morals, the fact that you won by cheating is not going to bother you.

So you just want to win.

Absolutely.

And over the last 25 years, I was privileged to work in elite sport.

I have dealt with people who have been caught and actually worked with them in an interview.

And they're a mixed group again of people.

Some have no regrets at all.