A British man has been arrested in Australia in connection with the theft of a rare pink diamond valued at $180,000 USD.

Australian authorities ordered the man to be x-rayed in case he had swallowed the jewel, the AFP reported.

Matthew Osborne, a 29-year-old British tourist, was arrested before boarding an international flight in Melbourne, according to Australian media.

The 4.3-millimeter diamond went missing on Saturday from a Queensland jewelry store, where owner Keith Bird said the suspect asked for a closer look at the jewel and then snatched it away before fleeing.

Bird, who described the diamond as "rare as hen's teeth," especially hopes the jewel will be returned since a buyer has expressed interest.

"We do have a buyer for it--a local buyer," he told the AFP. "A lot of people are buying them because they are going up in value."

Osborne faces theft charges, and authorities are still on the lookout for the missing gem.

"He is expected to appear in the Cairns Magistrates Court tomorrow charged with entering premises and stealing property," police said.

"The stolen diamond is still outstanding and investigations are continuing."

Pink diamonds have seen a meteoric rise in popularity in the past two decades, making the jewel the more valuable. Scientists don't know exactly how the jewels get their unique pink tint, but experts theorize that the color comes from a "molecular distortion."

Osborne allegedly took the rare gem from Bird's hands and then fled on a mountain bike. He was tracked to Melbourne when police used his fingerprints and CCTV images, according to the AFP.

"The x-rays are inconclusive at this time," Sgt. Greg Giles told media including the AFP.

"They haven't shown that the diamond has been swallowed, so we are making some follow-up inquiries."

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