The word “gold” appears 26 times in the federal indictment unsealed Friday against Senator Robert Menendez of New Jersey along with his wife, Nadine, and three businessmen.

There are details about the senator’s internet searches for the price of gold and Ms. Menendez’s trip to a jeweler to sell gold and photos of the serial numbers stamped on some of the 13 gold bars found in their home.

Yet gold is rarely mentioned in the financial disclosure forms he is required to file annually as a senator, showing up for the first time last year.

The three-count indictment — which charged the couple with accepting bribes in exchange for Mr. Menendez’s willingness to use his clout as a powerful Democratic senator — raises questions about the accuracy of those disclosure forms.

Mr. Menendez, the indictment said, “did not disclose” the receipt of car payments or “any cash or gold bars” — in the “relevant calendar year.”

The 39-page indictment depicts a far-reaching web of political corruption involving aid and weapons sales to Egypt and efforts by Mr. Menendez to persuade state and federal prosecutors to go easy on his associates in criminal cases. The reporting lapses that federal prosecutors in Manhattan noted on his Senate financial disclosure forms might seem to pale in comparison.

But they could also suggest an effort to hide his newfound wealth to evade notice by the Senate’s Select Committee on Ethics.

That could also be a crime.

“Knowingly and willfully filing a false personal financial disclosure report can result in a civil penalty of up to $50,000,” Brett Kappel, a Washington-based lawyer and expert in campaign finance, lobbying and government ethics, said in an email. “It may also be prosecuted as a violation of the False Statements Act — a felony punishable by up to five years in prison.”

The first mention of gold on Mr. Menendez’s financial disclosure report came in March 2022, on a report amended to indicate that in 2020 his wife owned as much as $250,000 in bullion. The alteration made it appear that Ms. Menendez had possessed the gold since before or soon after the couple married in October 2020.

But prosecutors believe she received at least some gold in 2021 or beyond; that acquisition does not appear in the senator’s disclosure reports.

Nadine Menendez, 56, was unemployed and struggling financially when she and Mr. Menendez began dating in February 2018, according to court records, the indictment and several of her acquaintances.

Many of the text messages investigators found on Ms. Menendez’s cellphone suggested she was desperate for money.

In July 2019, Wael Hana, a friend of Ms. Menendez’s who is also charged with bribery, gave her $23,000 to pay down mortgage debt and avoid losing her home to foreclosure, according to the indictment. Prosecutors believe the payment was part of the broader bribery scheme.

Several months later, she complained to Mr. Menendez that Mr. Hana had not provided additional payments she had expected.

“I am soooooo upset,” she wrote, according to the indictment, adding that she thought the money would have arrived, but for “the second day in a row there is nothing.”

She asked the senator how she should proceed. “You should not text or email,” he replied.

She and Mr. Menendez got engaged the next month during a trip to India and married a year later.

The items that prosecutors said constituted bribes continued to arrive in 2021 in the form of household items, including exercise machines and air purifiers.

The first transaction involving gold mentioned in the indictment is not until June 2021, when, prosecutors said, Mr. Hana purchased 22 one-ounce bars of bullion, two of which were found during a 2022 search of the Menendezes’ home. The purchase occurred two days after a private meeting in a Washington hotel between the senator and an Egyptian official, the indictment said.

Eleven additional bricks of gold, with serial numbers traced to a fund-raiser for Mr. Menendez, were also discovered in the home.

Mr. Menendez’s Senate disclosure forms indicate that, together, he and Ms. Menendez maintained seven bank accounts. But investigators also found $550,000 in cash during searches of a safe deposit box and the couple’s Englewood Cliffs, N.J., home, some of it stuffed into 10 envelopes and hidden in clothing and closets.

Mr. Menendez’s fingerprints were found on one of the envelopes, the indictment said.

Mr. Menendez said Friday that he was confident “that this matter will be successfully resolved once all of the facts are presented.”

He presented himself as a victim of overzealous prosecutors and said he believed he had been repeatedly targeted in federal investigations because he is Latino.

He is expected to address the charges at a news conference Monday in Union City, N.J., where he was raised and where he once served as mayor.

Ms. Menendez’s lawyer said she had broken no laws and planned to “vigorously contest these charges in court.”

Mr. Hana’s spokeswoman said the charges “have absolutely no merit.”

Despite the apparent financial disclosure omissions noted by prosecutors, it appears unlikely that the Senate’s Select Committee on Ethics would scrutinize Mr. Menendez’s filings while a criminal prosecution is pending.

“Absent special circumstances,” the committee said Friday, “it has been the longstanding policy of the committee to yield investigation into matters where there is an active and ongoing criminal investigation or proceeding so as not to interfere in that process.”