Former Los Angeles Sheriff Lee Baca has agreed to plead guilty to lying to investigators during a federal corruption probe that tainted his career, federal prosecutors said Wednesday.

Baca resigned from the helm of the nation's largest sheriff's department in 2014 amid the probe that led to charges against underlings for beating inmates and for trying to thwart an FBI investigation into those beatings.

U.S. Attorney Eileen Decker scheduled an afternoon news conference to announce that Baca had agreed to plead guilty to a charge of lying to federal investigators during the civil rights investigation.

Baca, who ran the department for more than 15 years, has said previously that he wasn't aware of abuses at the jail or efforts by underlings to stifle the FBI probe by hiding an inmate informant.

With his guilty plea, Baca would be the 18th former member of the department convicted in the case, according to U.S attorney's spokesman Thom Mrozek.

Baca avoided charges for years as prosecutors moved up the ranks to indict a number of officers and, eventually, his second-in-command.

In May, when former Undersheriff Paul Tanaka and another high-ranking member of the department were charged with obstructing justice, prosecutors declined to comment on whether Baca was under investigation.

Tanaka is facing trial, but his co-defendant, former Capt. Tom Carey, pleaded guilty and agreed to testify in related court proceedings. It's not clear if that included providing grand jury testimony against Baca.

Members of the department have been convicted of federal crimes, including beating inmates, obstructing justice, bribery and conspiracy. The convictions stem from a grand jury investigation that began in 2010 into allegations of abuse and corruption at the downtown Men's Central Jail.

Deputies tried to hide an FBI jail informant from his handlers for two weeks in 2011 by shifting him from cell to cell at various jails under different names and altering jail computer records. The FBI wanted the informant to testify to a grand jury.

Tanaka retired from the department in 2013 and ran unsuccessfully to replace his former boss, losing by a wide margin to Jim McDonnell.