US Senator Bob Menendez and his wife have pleaded not guilty to bribery charges as the FBI opens a counterintelligence probe into the senator’s ties with Egyptian officials.
The New Jersey senator is accused of accepting gold bars and hundreds of thousands of dollars in bribes.
Prosecutors allege he used his influence to help Egypt’s government, and business associates in New Jersey.
The senator has rejected calls from fellow Democrats to resign.
The Department of Justice indicted Mr Menendez and his wife, Nadine, on Friday on charges of bribery, conspiracy to commit extortion, and conspiracy to commit honest services fraud.
In addition to the federal bribery charges, the FBI is now looking into any possible wrongdoing between the senator and Egyptian officials, according to CBS News, the BBC’s US partner.
Though Mr Menendez has stepped down as the chairman of the Senate Foreign Relations Committee, he is facing growing calls to resign from fellow lawmakers, including those from his own party.
While he was chairman of the committee, he helped oversee billions of dollars in US aid to Egypt.
Mr Menendez’s alleged link to Egypt, has prompted calls within US Congress to re-examine $235m (£193.5m) in military aid to Cairo.
Chair of the Senate Foreign Relations Committee’s Middle East subcommittee, Democratic Senator Chris Murphy said, “I would hope that our committee would consider using any ability it has to put a pause on those dollars, pending an inquiry into what Egypt was doing.”
Mr Menendez, 69, has previously faced bribery charges but that case ended in a mistrial in 2017.
During a search of the senator’s New Jersey home last year, investigators found $480,000 (£393,000) in cash hidden throughout the residence, as well as 13 bars of gold bullion worth an estimated $155,000 (£127,000), prosecutors allege.
The federal indictment also alleges Mr Menendez and his wife received “payments towards a home mortgage, a low or no show job, a luxury vehicle, and other things of value”.
Agents say they found a luxury Mercedes-Benz paid for by one of the businessmen parked in the couple’s garage.
Three businessmen were also charged in the indictment. One of them, Wael Hana, was arraigned on Tuesday and pleaded not guilty.