WASHINGTON (AP) — Florida Sen. Marco Rubio announced that he fired his chief of staff after getting reports of “improper conduct” with subordinate staffers.

The statement from Rubio’s office was released Saturday evening. His office did not respond to requests for details on Sunday.

The statement said Rubio had been made aware of “allegations of improper conduct by my Chief of Staff while under the employment of my office,” Rubio wrote.

He added that he had “sufficient evidence to conclude that while employed by this office, my Chief of Staff had violated office policies regarding proper relations between a supervisor and their subordinates. I further concluded that this led to actions which … amounted to threats to withhold employment benefits,” Rubio said in a statement. Rubio’s office said it will not be disclosing further details.

The Florida Republican said his office will notify appropriate congressional and Senate administrative offices of the matter on Monday.

The announcement made no mention of the chief of staff’s name. However, a press release on Rubio’s website dated December 2016 said identified Clint Reed as Rubio’s newly appointed chief of staff.

“For over a year, I’ve gotten to know and work closely with Clint on my campaigns, including two in Florida. He’s a superb manager who loves Florida, has earned my trust, and relishes the challenge of solving tough problems,” Rubio wrote at the time.

Reed, who describes himself on social media as Rubio’s chief of staff, did not return a call or a Facebook message for comment.

Reed managed Rubio’s 2016 re-election campaign to the U.S. Senate as well as Rubio’s presidential primary campaigns in Florida and elsewhere. Reed also served as regional political director for the Republican National Committee and executive director of the Republican Party of Arkansas.

A native of Arkansas, Reed has been a partner at Little Rock-based Impact Management Group, a public affairs firm that counts the Republican Governors Association among its clients.