The charges are part of an expanding U.S. Justice Department investigation into alleged misspending at UAW union training centres.

The U.S. Attorney's Office for the Eastern District of Michigan said charges had been filed against Nancy Johnson, 57, who served as the second most senior UAW official responsible for the union's FCA department from 2014 to 2016.

Johnson was charged with participating in a conspiracy in which she and other union officials "accepted a stream of concealed payments and things of value from FCA executives in the months leading up to the 2015 collective bargaining negotiations," the attorney's office said in a statement.

Johnson could not be reached for comment and a lawyer for Johnson could not immediately be identified. According to court documents, she illegally accepted tens of thousands of dollars worth of designer clothing, golf resort fees, luxury accommodations and first-class travel.

In a statement the UAW said the "illegal misconduct alleged in today’s indictment is appalling and runs counter" to the union's values.

The union said Johnson was removed from the union in July 2016, adding there is "no evidence that compromised individuals involved in this investigation, including Ms. Johnson, in any way corrupted the negotiations of the terms of the collective bargaining agreement" in 2015.

Alphons Iacobelli, 58, a former vice president of employee relations at Fiat Chrysler, pleaded guilty in January to making at least $1.5 million (£1 million) in improper payments to UAW officials.

Iacobelli's plea agreement states that he paid out FCA funds in cash and items of value to UAW officials and employees to obtain concessions for FCA in negotiating and implementing collective bargaining agreements between the automaker and the union, and to influence union decisions on pension funds.

Last month, the widow of former UAW Vice President General Holiefield, the union official at the centre of the U.S. probe, pleaded guilty to tax fraud in relation to the case. Holiefield died in March 2015.

(Reporting by Nick Carey; Editing by Tom Brown)

By Nick Carey