San Jose police said they will launch an investigation of a jeweler who admitted selling poor-quality diamonds to customers.

SLIDESHOW: South Bay Jeweler Admits Lies

Dan Mokma admitted to NBC11 this week that he was not honest about the quality of diamonds he sold some customers.

Now the San Jose police Fraud Unit is receiving calls from customers who are worried Mokma may have tricked them, too.

"In regards to the NBC11 newscast that you guys did, we have had a couple of people who called our department in regards to that establishment and that particular person who runs that establishment," San Jose Police Department spokesman Jermaine Thomas said.

Mokma told NBC11 that he's trying to work out the issue with his customers. Police are looking to work with the district attorney on the case.