Sanitation workers in Modesto, Calif., received an unexpected surprise Wednesday on a routine cleaning expedition: Gold, worth $2,500.

"[It was] from the city sewer traps, and they cleaned it up," Modesto Gold, Jewelry and Coins employee Yvonne Brawley told ABC affiliate News 10. "And some of it wasn't gold and some of it was."

The majority of the gold jewelry appeared to be in twisted fragments, stained and discolored from being submerged in the sewer, which spans 641 miles within the city.

Modesto police told News10 they are investigating the workers who sold the gold to explore whether the jewelry was really found in the sewer, or elsewhere. A routine audit of the pawn shop led the police to begin an investigation, which began earlier this year, and was prompted by the sales that occurred over the course of a couple of months.

Brawley said the three employees, two men and one woman, came into her store wearing their City of Modesto uniforms. She said the woman had sold jewelry several times over the course of a couple of years and that she has also sold jewelry at a pawn shop in Oakdale, Calif. The two men sold jewelry at Modesto Gold, Jewelry and Coins one time last month, she said.

According to police, the investigation is nearing completion. Officials said they will not comment on the identity of the workers because the investigation has not been completed.

Either way, Brawley said she hopes the employees get to keep the money received for the jewelry.

"They should be able to keep it if they found it. Nobody's going to want it. It took a lot of work trying to get that out," she said.