The head of a large and politically powerful Minnesota union, Council 5 of the American Federation of State, County and Municipal Employees, has been suspended from his job pending an investigation of unidentified allegations.

John Westmoreland, AFSCME Council 5’s executive director, has been put on “temporary investigative leave,” said Emily Weber, a union spokeswoman, on Tuesday. Council 5’s executive board Friday named former top AFSCME leader Peter Benner as interim executive director.

The executive board last week “learned of allegations regarding staff of AFSCME Council 5,” the union said in a statement. Council 5 wouldn’t comment further on the allegations, but said an “outside entity” has been brought in to conduct an investigation.

Westmoreland could not be reached for comment.

South St. Paul-based Council 5 is an umbrella group for many AFSCME local unions, which together represent 43,000 state and local government workers in Minnesota. Council 5 has long been a critical base of support for Minnesota’s DFL Party.

Westmoreland ascended to the union’s top job in November 2017 after the retirement of longtime AFSCME leader Eliot Seide. Westmoreland had previously been Council 5’s assistant director and had also held other AFSCME positions. He became involved in the union while working as a prison guard in Stillwater.

Council 5 is the largest of two AFSCME councils in Minnesota. Benner, the interim director, was executive director of AFSCME Council 6 in Minnesota from 1982 to 2005, when it was merged with Council 5.