Electric-vehicle manufacturer BYD Co. Ltd. defended itself on Monday from charges that it did not comply with minimum wage laws for engineers working at its Lancaster plant and North American headquarters in downtown Los Angeles.

The Chinese company, which has a contract to manufacture buses for the Los Angeles County Metropolitan Transportation Authority, issued a press release in response to an investigation by the state Department of Industrial Relations, which prompted a picket outside the L.A. offices.

The company, based in the industrial city of Shenzhen, said its engineers, battery specialists and bus-design specialists are only in California temporarily to train its U.S. workforce on BYD’s electric-bus and battery-charging technology.

It stated the Chinese engineers earn $2,200 a month while here, and also receive free housing and use of company vehicles.

“These knowledge experts are not displacing any American workers; rather, they are training and providing support to the approximately 40 California-based employees who BYD already has hired to start up its operations,” the release said. “BYD always considers these engineers as its most valuable asset.”

The Department of Industrial Relations has specifically cited BYD for not paying minimum wage nor providing worker’s compensation insurance, failure to provide itemized wage statements and not giving a second brief rest break. The department has already levied $99,245 in fines against the company.

The citations prompted an Oct. 30 protest outside the Los Angeles headquarters by the Los Angeles Alliance for a New Economy, a left-leaning economic and social-justice organization.

BYD has hired international law firm Paul Hastings LLP to represent it in the on-going state investigation.

Warren Buffett’s Berkshire Hathaway Inc. has about a 10 percent stake in the manufacturer.