Clint Reed, who became Rubio's chief of staff in December 2016, was terminated "effective immediately," Rubio said in a statement.
"Yesterday afternoon, I was made aware, for the first time, of allegations of improper conduct by my Chief of Staff while under the employment of my office," Rubio said Saturday. "These allegations were reported directly to me instead of our General Counsel or the Congressional Office of Compliance. Immediately upon receiving this complaint, I along with our General Counsel, began an investigation of this matter."
Reed was a senior advisor on the 2016 Rubio campaign, where he ran political operations in Iowa, South Carolina and Florida. He also previously worked at the Republican National Committee as a regional political director.
Rubio wasted no time in getting rid of Reed after hearing about the allegations.
"This evening, I traveled from Florida to Washington D.C. and terminated his employment effective immediately," he said. "We have taken steps to ensure that those impacted by this conduct have access to any services they may require now or in the future."
Rubio continued: "By early this afternoon, I 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 in my judgment amounted to threats to withhold employment benefits."
A native of Arkansas, Reed went to Lyon College for his undergraduate studies, and earned his master's degree from the University of Arkansas, according to information Rubio's office release when Reed he was hired as chief of staff. He made numerous political stops after that: he worked for Georgia Sen. Saxy Chambliss' campaign; served as executive director of the Republican Party of Arkansas; and managed grassroots operations in his home state for the 2004 Bush-Cheney re-election campaign.
Reed could not be reached for comment.
Rubio, meanwhile, said to the wishes of the victims, "we will not be disclosing any further details about the incidents which occurred."
On Monday morning, Rubio's office "will be formally notifying the appropriate Congressional and Senate administrative offices of this matter when they return to work," he said.