Senator Robert Menendez of New Jersey is expected to appear in Manhattan federal court on Wednesday morning to be arraigned on federal bribery charges for the second time in eight years.

Mr. Menendez, a Democrat, is accused of using his political clout to assist the government of Egypt and three New Jersey businessmen in exchange for hundreds of thousands of dollars, bars of gold bullion and a Mercedes-Benz convertible.

Nadine Menendez, 56, the senator’s wife of three years, is also expected to be arraigned, alongside her husband, in the federal court after being charged with participating in the yearslong bribery scheme.

One of the businessmen, Wael Hana, a U.S. citizen born in Egypt, was arrested Tuesday morning at Kennedy International Airport after he voluntarily flew to the United States from Egypt to face federal charges in Manhattan, his lawyer said. He pleaded not guilty hours later, surrendered his passport and was granted release on a $5 million personal recognizance bond.

The conspiracy as alleged by prosecutors was far-reaching and depicted a web of corruption that even one of the senator’s closest political allies, Senator Cory Booker of New Jersey, called shocking and disturbing.

Mr. Menendez, 69, has said in recent days that he was confident that he would be exonerated once the facts were fully presented, and he has cautioned against a rush to judgment. He has rejected calls from a growing number of top Democrats, including Gov. Philip D. Murphy and Mr. Booker, to step down.

Two associates of Mr. Hana who are also charged in the 39-page indictment — Fred Daibes, a prominent New Jersey real estate developer and fund-raiser for Mr. Menendez, and Jose Uribe, who works in the trucking industry — are also expected to appear in court on Wednesday.

The scheme involved payments by the three businessmen to Mr. Menendez and his wife in exchange for the senator’s efforts to direct federal aid and weapons sales to Egypt, according to the indictment. This, prosecutors said, also benefited Mr. Hana’s halal meat business, which eventually won a contract to be the sole entity permitted by Egypt to certify that imported food products had been prepared according to Islamic law.

Prosecutors said Mr. Hana used his company to funnel bribes to the Menendezes.

“Seems like halal went through,” Ms. Menendez said in a text to the senator, the indictment said. “It might be a fantastic 2019 all the way around.”

When a high-level U.S. Department of Agriculture official publicly objected to the monopoly, concerned that it could increase the cost of food in Egypt and disrupt U.S. markets, Mr. Menendez tried to silence the official, the indictment said.

Mr. Menendez is also accused of intervening in criminal investigations involving people tied to the Egyptian scheme.

Investigators found $550,000 in cash, 13 bars of gold bullion and the Mercedes during a June 2022 search of the couple’s home in Englewood Cliffs, N.J., and a safe deposit box in Ms. Menendez’s name.

The new charges come after a lengthy investigation led by the Federal Bureau of Investigation and prosecutors in the Southern District of New York. Much of the alleged activity occurred in New Jersey. But prosecutors noted that parts of the conspiracy, including a dinner meeting and sales of gold in Manhattan, and the use of a bank account first opened in the Bronx, took place within the Southern District’s jurisdiction.

“My office is firmly committed to rooting out corruption, without fear or favor, and without any regard to partisan politics,” Damian Williams, the U.S. attorney for the Southern District, said in a statement. “We will continue to do so.”

Mr. Menendez was charged in 2015 in New Jersey with similar, but unrelated, corrupt acts by federal prosecutors in New Jersey. His federal trial in Newark lasted nine weeks, but the jury could not reach a unanimous decision. In January 2018, the Justice Department declined to retry him after a judge dismissed the most serious charges.

Prosecutors say the corruption scheme laid out in the 39-page indictment unsealed Friday began the next month.

Benjamin Weiser contributed reporting.