The authorities fanned out across one of the largest jail facilities on Rikers Island and searched over 100 correction officers for contraband on Monday as part of a large scale investigation into drug trafficking and other criminal activity inside the complex.

Dozens of officials from the Department of Correction and the Department of Investigation searched the George Motchan Detention Center, inspecting 75 different locations, including inmate cells and employee common areas, the authorities said. The center houses over 1,900 inmates. It was not immediately clear what officials discovered on Monday, though both departments issued a statement that said arrests were anticipated.

For several months now, the Department of Investigation has been looking into allegations of wrongdoing by correction personnel at Rikers, said a law enforcement official who spoke on the condition of anonymity. More than a dozen correction officers and their superiors have been referred for prosecution, suspected of drug trafficking, inmate assault, evidence tampering and falsifying documents to cover up criminality, the official said.

The Correction Department employs about 9,000 uniformed officers, with the majority of them working at Rikers.