A taxi driver in New York City returned a black bag carrying diamond rings to a passenger who had earlier paid him a 30 cent tip on an $11 ride, according to media reports.

The bag, which was left in the trunk of the car, contained two small display cases with 31 diamond rings tucked inside, the New York Daily News reports.

Hours after Osman Chowdhury, a native of Bangladesh, had dropped off the passenger, he tracked her down through a flurry of phone calls and returned the bag, which she had left in the taxi’s trunk, the AP reports.

It appears likely that the woman, who was only identified as a jeweler, was attending the JCK Invitational since Chowdhury drove her from the Hilton New York to an E. 35th St. apartment building Monday night, the Daily News reports. The fare was $10.70. She gave him a $20 and asked for $9 back.

The AP reports that the jeweler offered a $100 reward for the bag of jewelry. Chowdhury reportedly said he reluctantly accepted the money to cover the fares he lost while tracking her down.

Chowdhury told the Daily News that he never thought of keeping the gems.

JCK