The investigators from the Bureau of Prisons, the Justice Department's inspector general's office and other law enforcement agencies descended on the Metropolitan Detention Center in Brooklyn, the Bureau of Prisons said in a statement to The Associated Press.
The law enforcement operation was "designed to achieve our shared goal of maintaining a safe environment for both our employees and the incarcerated individuals housed at MDC Brooklyn," the agency said.
Prison officials declined to provide specific details about the operation Monday morning.
Combs' lawyers have highlighted a litany of horrors at the jail - including deplorable conditions, rampant violence and multiple deaths - as they've made repeated attempts to get him released on bail while he awaits trial next May on sex trafficking charges.
The hip-hop mogul's detention and a rash of crimes connected to the jail in recent months have further galvanized public interest, leading to increased scrutiny and a push by the Justice Department and Bureau of Prisons to fix problems and hold perpetrators accountable.
Last month, federal prosecutors charged nine inmates in a spate of attacks from April to August at the Metropolitan Detention Center, the only federal jail in New York City. The allegations detailed serious safety and security issues at the jail, including charges after two inmates were stabbed to death and another was speared in the spine with a makeshift icepick. A correctional officer was also charged with shooting at a car during an unauthorized high-speed chase.
Earlier this month, an inmate was charged in a murder-for-hire plot that led to the death of a 28-year-old woman last December outside a New York City nightclub. According to prosecutors, the inmate used a contraband cellphone to orchestrate the plot from behind bars while awaiting sentencing for directing a different shooting years earlier.
The criminal charges offered a window into the violence and dysfunction that have plagued the jail, which houses about 1,200 people, including Combs and Sam Bankman-Fried, the founder of the collapsed FTX cryptocurrency exchange. The total is down from more than 1,600 in January.
In a statement on Monday, the Bureau of Prisons said its operation in Brooklyn had been planned in advance and there was "no active threat."
The agency said it wouldn't provide additional details about what investigators were doing until the operation was complete "in an effort to maintain the safety and security of all personnel inside the facility and the integrity of this operation."
The facility, in an industrial area on the Brooklyn waterfront, is used mainly for post-arrest detention for people awaiting trial in federal courts in Manhattan or Brooklyn. Other inmates are there to serve short sentences following convictions.
Those held at the Brooklyn jail have long complained about violence, dreadful conditions, severe staffing shortages and the widespread smuggling of drugs and other contraband, some of it facilitated by employees. At the same time, they say they've been subject to frequent lockdowns and have been barred from leaving their cells for visits, calls, showers or exercise.
Twice denied bail, Combs is now asking the 2nd U.S. Circuit Court of Appeals to grant his release. Arguments are scheduled for Nov. 4.
Combs lawyer Mark Agnifilo, who had previously sought to have him moved to a jail in New Jersey, said at an Oct. 10 hearing: "We're making a go of the MDC. The MDC has been very responsive for us."
Another Combs lawyer, Anthony Ricco, told reporters outside the courthouse afterward: "He's doing fine. It's a difficult circumstance. He's making the best of the situation."
But, Ricco added: "Nobody's OK with staying in jail for now."