BERLIN - A German thief who swallowed a ring he had stolen was betrayed by his own body when he suffered stomach pains during police interrogation.

He was taken to hospital where an x-ray revealed the hidden loot.

Off-duty police officers in the western town of Bergisch Gladbach thought they had seen the 30-year-old stealing something from a shop window, but only found an empty box when they searched him, a police spokesman said Friday.

"He said he'd grabbed the box and found it empty, but the shopkeeper said there was a ring missing," he said. "Then during questioning he complained of severe stomach pains and was rushed to hospital with suspected appendicitis."

Doctors x-rayed the man and discovered the ring, which they fished out using pincers attached to a stomach tube.

"It seems that the pains were coincidental and had nothing to do with the ring," the police spokesman said. He did not know what had caused the pains.