A federal regulator on Monday ordered Wells Fargo to pay $5.4 million to a former manager who said he was fired in 2010 after reporting to his supervisors and to a bank ethics hotline what he suspected was fraudulent behavior.

The bank must also rehire him, the Labor Department’s Occupational Safety and Health Administration said.

The $5.4 million, intended to cover back pay, compensatory damages and legal fees, is the largest individual award ever ordered through OSHA’s whistle-blower protection program, according to Barbara Goto, the agency’s regional administrator in San Francisco.