Federal prosecutors on Thursday announced an additional charge against New Jersey Democratic Sen. Bob Menendez and his wife, alleging they conspired to have the senator act as a foreign agent of Egypt.

The superseding indictment filed against Menendez, who was chairman of the Senate Foreign Relations Committee at the time of the alleged actions, adds a new dimension to the case by alleging a US senator was working on behalf of another country.

Menendez and his wife, Nadine Arslanian Menendez, were indicted last month on corruption-related offenses, and are accused of accepting “hundreds of thousands of dollars in bribes” in exchange for the senator’s influence.

Prosecutors had alleged the bribes included gold, cash, home mortgage payments, compensation for a “low-or-no-show job” and a luxury vehicle.

Both Menendez and his wife have pleaded not guilty. A trial date has been set for May.

Menendez has refused calls from his fellow Democrats to resign, but has not said if he will run for reelection next year. The new charge carries a maximum sentence of five years in prison. Menendez and his wife are now facing as much as 50 years in prison if convicted.

According to the alleged scheme, Menendez met with an Egyptian intelligence official at his Senate office in 2019, along with his wife and New Jersey businessman Wael Hana where they discussed a human rights issue involving Egypt and a US citizen injured in an airstrike in 2015. Certain members of Congress believed Egypt had not provided fair compensation to the American injured in the attack, causing them to object to provide military aid to Egypt.

Following the meeting, prosecutors allege, Menendez searched the name of the injured American and his claim. One week later, the Egyptian official texted Hana in Arabic stating if Menendez helped resolve the issue, “he will sit very comfortably.” Hana replied, “orders, consider it done.”

The following year, in March 2020, prosecutors allege that Nadine Menendez texted one of the Egyptian officials, “anytime you need anything you have my number and we will make everything happen.” A few days later, she arranged a meeting between the Egyptian official and the senator to discuss negotiations between Egypt, Sudan, and Ethiopia over a dam Ethiopia was constructing on the Nile River. The dam’s construction was a key foreign policy concern of Egypt, prosecutors allege.

Within a month, prosecutors allege, Menendez wrote a letter to the US Treasury secretary and secretary of State to “express my concern” about the stalled negotiations over the dam. “I therefore urge you to significantly increase the State Department’s engagement on negotiations surrounding the [Dam],” the letter said.

Prosecutors allege Menendez knew about the foreign agent law. It is illegal for a member of Congress or any public official to act as foreign agent. Prosecutors allege Nadine Menendez and Hana failed to register as agents working on behalf of Egypt and conspired to have Menendez act on behalf of Egypt. Hana has previously pleaded not guilty.

In May 2022, Menendez sent a letter Attorney General Merrick Garland to follow up on an earlier request to prosecutors to open the investigation into the former lawmaker, David Rivera, alleging he had worked on behalf of a Venezuela state-owned oil company.

Hana’s attorney Lawrence Lustberg rejected the new allegations.

“The new allegation that Wael Hana was part of a plot concocted over dinner to enlist Senator Menendez as an agent of the Egyptian Government is as absurd as it is false,” Lustberg said. “As with the other charges in this indictment, Mr. Hana will vigorously defend against this new and baseless allegation.”

Lawyers for Menendez could not immediately be reached for comment on the new charge.

This story has been updated with additional details.