Five people who worked at the Rikers Island jail complex in New York City, as well as a detainee there, have been charged with corruption, including smuggling contraband into the jail, according to three complaints unsealed in Manhattan federal court on Tuesday.

Federal prosecutors said that in 2021 and 2022, several former city correction officers, a Department of Correction employee and an employee of a department contractor accepted bribes to smuggle in cellphones, oxycodone, marijuana, fentanyl and a synthetic drug known as K2.

Their actions made Rikers Island “less safe, for inmates and officers alike,” Damian Williams, the U.S. attorney for the Southern District of New York, said in a statement, adding that the defendants “engaged in corruption for their own enrichment.”

Five of the defendants were arrested on Tuesday; the sixth was already in state custody. Lawyers for the defendants could not immediately be identified.

During the period in which the officers and other employees are accused of smuggling drugs into the jail, visitation had stopped because of the coronavirus pandemic, but the number of overdoses in the city’s jail system had spiked.

In 2021, were 113 overdoses in city jails that required a 911 call — a 55 percent increase from the previous year, according to data from Correctional Health Services, the agency that provides health care to detainees. In 2022, five of the 19 people who died in the jails or soon after release had overdosed on drugs.

In one of the unsealed complaints, investigators said that from December 2021 through February 2022, Carlos Rivera, 27, of Yonkers, N.Y., a correction officer at the North Infirmary Command at the time, met in the Bronx with associates of an detainee to pick up contraband, including cellphones and drugs, to bring into the jail for that inmate.

During an interview with officials in June 2022, Mr. Rivera estimated that he had received around $500 in bribes via Cash App, a mobile payment service, according to the complaint.

Mr. Rivera was charged with conspiracy to commit honest services wire fraud and conspiracy to distribute narcotics and controlled substances. Each charge carries a maximum penalty of 20 years in prison.

In another complaint, investigators said that from March through at least April 2022, Chantal de los Santos, 30, a former correction officer, worked with two inmates to bribe Shanequa Washington, 39, a correction program counselor, to smuggle contraband into the jail.

Ms. de los Santos gave Ms. Washington paper sheets that federal authorities believe were soaked in controlled substances. Ms. Washington brought the sheets into the jail and gave them to an inmate with whom she was in a romantic relationship, investigators said. That inmate and another detainee then sold some of the sheets to other inmates.

Ms. Washington received at least $4,000 in payments from the sale of the sheets, the complaint said. After smuggling in sheets on another occasion, she received more than $6,500 on Cash App.

Ms. de los Santos also worked with inmates to bribe Kenneth Webster, 42, who worked for a contractor that provided services at Rikers Island, to smuggle in contraband, the complaint said. Ms. de los Santos gave Mr. Webster cigarettes, alcohol, cellphones, electronic tablets and paper sheets that appeared to be soaked in controlled substances. Mr. Webster brought the contraband to two inmates, who later sold it to others; in return, Ms. de los Santos paid him in cash, investigators said.

Ms. de los Santos was charged with one count of conspiracy to commit bribery, which carries a maximum penalty of five years in prison. She was also charged with two counts of conspiracy to commit honest services wire fraud.

Ms. Washington and Mr. Webster were charged with conspiracy to commit honest services wire fraud; Ms. Washington was also charged with conspiracy to commit bribery.

In the third complaint, investigators said that roughly between July and August 2021, Stephanie Davila, 30, a former correction officer, conspired with Kristopher Francisco, 29, an inmate, to bribe another correction officer to smuggle in contraband. Ms. Davila and Mr. Francisco were in a romantic relationship and paid the other officer cash to smuggle in fentanyl, marijuana, K2, cigarettes and cellphones, the complaint said.

Ms. Davila and Mr. Francisco were both charged with conspiracy to commit bribery, conspiracy to commit honest services wire fraud and conspiracy to distribute narcotics and controlled substances. The other correction officer is a cooperating witness.

After the complaints were unsealed, the New York City Department of Investigation issued eight recommendations, including that the Correction Department place canine units at the staff entrance at Rikers to screen correction officers for drugs and that it hire contractors or external law enforcement to serve as front gate staff.

The unsealing of the complaints comes amid efforts to close the troubled jail complex, which has been under scrutiny over high rates of violence and reports of unsafe conditions for detainees. New York City this week agreed to pay more than $28 million to settle a lawsuit filed by the family of a man who suffered severe brain damage after he tried to hang himself in a Rikers Island jail cell as several correction officers stood by.

Jan Ransom contributed reporting.