Authorities say a former California councilman has agreed to plead guilty to bribery after authorities said he accepted $2.3 million.

Thom Mrozek, a spokesman for the U.S. attorney's office, says the bribe is believed to be the largest ever accepted by a U.S. public official in an undercover operation.

Federal prosecutors announced Tuesday that 64-year-old Marcelo Co, an ex-Moreno Valley city councilman, will plead guilty to one count each of bribery and filing a false tax return. He could face up to 13 years in prison.

Co agreed to sell a 30-acre parcel he owned to the operative for $5.3 million. Prosecutors say Co then pocketed $2.3 million.

A message left for Co's attorney, Brian Newman, was not immediately returned.