The top official at one of Minnesota’s biggest labor unions has been placed on leave pending an investigation into unspecified allegations, the American Federation of State County and Municipal Employees Council 5 said Tuesday.

In a statement, the union said it has brought on a temporary leader while the inquiry into executive director John Westmoreland proceeds.

“Last week, the executive board learned of allegations regarding staff at AFSCME Council 5. The board made a decision to conduct a thorough investigation of these allegations,” the statement read. “An outside entity will lead this investigation to ensure impartiality through all aspects of the process.”

Westmoreland wasn’t immediately available to comment, according to a woman who answered a phone call to his home number.

During his absence, former labor leader Peter Benner, who has deep AFSCME ties, will run the union. The unsigned statement said no further information will be provided to protect the privacy of the parties involved.

AFSCME Council 5 is a power player in Minnesota Democratic politics, with more than 43,000 members across state and local government.

Council 5 has about 17,000 state employees under its umbrella, from clerical workers to prison officers to snowplow drivers.

The union’s political fund spent nearly $1.9 million in 2018 on state-level races. That includes $200,000 for ads and mailings promoting now-Gov. Tim Walz and much more supplied to groups that also spent heavily on the governor’s race and on behalf of DFLers running for the Legislature.

Westmoreland, a former prison corrections officer, took over the top spot in the union when longtime executive director Eliot Seide retired in 2017.

Upon becoming executive director, Westmoreland promised to strengthen the union’s communication and build coalitions at a time when organized labor was under various threats. He stressed his attention to detail and his plans to make the union’s local chapters more cohesive.

“I believe in our union. I have no idea how not to be a member of this union,” Westmoreland said in an interview posted on the union’s website. “It is who I am.”