3M Company filed a lawsuit on Monday in the US District Court for the Central District of California against an Amazon seller that purported to sell 3M N95 face masks and respirators at inflated prices.

The defendant, Mao Yu, is the owner of KM Brothers Inc., KMJ Trading Inc. and Supreme Sunrise, Inc. In the complaint, 3M alleges the defendant advertised and sold “authentic” N95 masks through three amazon accounts (Supreme Sunshine, Julian Trading, and KM Buy). Additionally, 3M claims the defendant has charged customers more than $350,000 for N95 face masks and respirators. Overall, the defendant’s listed price averaged 20 times 3M’s listed price.

3M’s complaint includes the following claims: trademark counterfeiting, trademark infringement, trademark dilution, unfair competition, false endorsement, false designation of origin, price-gouging and false advertising.

3M stated this lawsuit marks the twelfth federal lawsuit filed against fraudulent sales of N95 face masks during COVID-19. 3M further stated the company “is taking an active role to combat these activities.” For example, 3M established a site for people to report potential price-gouging. Additionally, 3M created a “3M COVID-19 Fraud hotline” where purchasers can call for information and help to detect fraud.

For more on COVID-19, see our special coverage.