QUEENSLAND police are patiently waiting for movement after an alleged robber swallowed two diamond rings in a bizarre jewellery store heist.

It's alleged the 50-year-old feigned interest in buying the rings at a Brisbane store on Friday, and fled with the precious gems in his hot little hands.

The shop attendant gave chase and he was nabbed with the help of some passers-by but when police arrived to arrest him, the booty was no where to be found.

"We believe they were swallowed. I do know that the rings are outstanding, yet to be recovered," a police spokeswoman told AAP on Tuesday.

The man, who remains in custody, is facing two charges of stealing and two counts of fraud.

He's due to face court again on December 13, when police hope they can offer irrefutable evidence that he was the culprit.