Investigators from the Federal Bureau of Investigation (FBI) and the US Internal Revenue Service (IRS) are investigating Menendez, who is accused of accepting bribes from real estate tycoon and former bank executive Fred Daibes, who is on trial for banking crimes, in exchange for using his connections at the Justice Department, NBC New York reported.

A federal grand jury in Manhattan heard testimony from witnesses in the probe, which alleges that Menendez, a New Jersey state senator, accepted about $400,000 worth of gold bullion through his wife, Nadine Arslanian.

NBC Legal Analyst Danny Cevallos said that under federal law, Menendez will be found guilty if it is proven that he accepted bribes promising to use his powers.

Daibes, who allegedly bribed Menendez, allegedly owed $1.8 million from "Mariner's Bank", of which he was the former president, and the verdict of the case was postponed three times in 2022.

After the bribery investigation against him began, Menendez announced that the gold bars were given to his family in 2020.

Also among the investigations against the senator is the fact that he took bribes in exchange for winning a tender from the Egypt-based startup company "IS EG Halal", which undertook halal certification across the US, despite having no experience in the sector.