Video: Australian Police Quiz British Man over 'Swallowed' £100,000 Diamond

A British tourist has been arrested after he swallowed a £100,000 diamond in a bid to steal the gem.

Matthew Osborne, 29, was detained by Australian police after he tried to flee to New Zealand from a Melbourne airport with the pink stone still in his stomach.

CCTV showed a man sprinting out of the Cairns jewellers at the weekend before he escaped on a bicycle.

The diamond's owner, Keith Bird, told Australian television that police told him the man had admitted stealing the diamond before he gulped it down.

However, he does not believe the British suspect swallowed the diamond and even though police took him straight to hospital, X-rays were unable to locate the expensive jewel.

"If he thought he'd got away with it, why would you sit at the Melbourne airport and swallow it, and if you have to go to the loo on a flight to New Zealand? That would be a bit dangerous," Mr Bird said.

"If he's not going to confess where the stone is, he's going to do some serious time."

Senior Sergeant Greg Giles added: "The X-rays are inconclusive at this time. They haven't shown that the diamond has been swallowed, so we are making some follow-up inquiries.

'We're hoping he realises it'll obviously be in his best interests if he cooperates with us so we are hoping to get it back."

Osborne is expected to be extradited from Melbourne to Cairns and charged with theft.