The case, brought by the Justice Department's public integrity unit, sets up a high-stakes battle between a New Jersey senator who has fought off investigations for years, and federal prosecutors and the FBI who have spent years pursuing him.

Feds preparing corruption charges against Democrat sen. 01:55

PLAY VIDEO

READ: Menendez says he's 'not going anywhere'

"Robert Menendez, a U.S. senator, and Dr. Salomon Melgen, a Florida ophthalmologist, were indicted today in connection with a bribery scheme in which Menendez allegedly accepted gifts from Melgen in exchange for using the power of his Senate office to benefit Melgen's financial and personal interests," said Peter Carr, a Justice Department spokesman, in a statement.

The two were indicted in the district of New Jersey for one count of conspiracy, one count of violating the travel act, eight counts of bribery and three counts of honest services fraud; Menendez was also charged with one count of making false statements, according to Carr's statement.

SEE: The full Menendez indictment

Federal officials and Menendez's attorneys had discussed plans for the New Jersey Democrat to turn himself in before a planned court hearing on Thursday, according to people briefed on the case.