“The sheer volume of bills that we encountered, which you can see in some of the photographs, was too much to count by hand,” Mr Kougemitros told the court.
The FBI also seized 11 mini-gold bars weighing 1oz, along with two 1kg gold bars. They were passed round to the jury.
In opening statements, prosecutors said Mr Menendez, who has been a senator since 2006, had “betrayed the people he was supposed to serve for bribes”.
They alleged that the cash and gold bars found in his home were gifted to him by Egyptian officials for political favours in Washington.
Prosecutor Lara Pomerantz also accused Mr Menendez of receiving a Mercedes-Benz in exchange for interfering with a criminal case involving Egyptian-American businessman Wael Hana, who is a co-defendant in the case.
Mrs Menendez is accused of being the go-between in these bribes.
Avi Weitzman, a lawyer for Mr Menendez, maintained his client took no bribes and did not violate the law. He added that some of the gold bars belonged to Mrs Menendez.
During opening statements on Wednesday, Mr Weitzman sought to shift fault to the senator’s wife, saying she had “kept him in the dark” on financial matters, and that the couple had separate bank accounts.
Lawyers for the other co-defendants in the case, Mr Hana and New Jersey real estate developer Fred Daibes – who is accused of giving cash and gold bars to Mr Menendez – told the court that their clients are long-time close friends of Mrs Menendez, and that they often traded gifts.
“Don’t let them say that every gift is a bribe,” said Lawrence Lustberg, a lawyer for Mr Hana.
Mr Menendez was the top-ranking Democrat on the Senate Foreign Relations Committee for more than five years, which gave him sway over US foreign policy. He was removed as chairman after he was charged.
He has been charged with 16 felony counts, including bribery, extortion, wire fraud, obstruction of justice and acting as a foreign agent, and faces prison time if convicted.
Mrs Menendez is due to be tried in July on bribery and corruption charges.
In 2017, Mr Menendez went on trial for criminally accepting favours from a Florida doctor, but that ended in a mistrial.