Sheriffs deputies report more and more counterfeit currency is turning up at businesses in Tuolumne County.

Another bogus $20 bill turned up over the weekend at the Black Oak Casino.

To help combat this crime, the casino is hosting a counterfeit currency detection seminar for businesses, 7 p.m. Thursday at the Tuolumne Rancheria Tribal Hall.

Casino spokesman Chris Martin says the evening workshop will give business owners a chance to learn from an expert on how to spot the bogus money.

U.S. Secret Service agent James Holcomb will teach the class.

Contact the Tuolumne County Economic Development Company office or the Black Oak Casino for more information.