NEWARK, N.J. — Sen. Robert Menendez only started paying big bucks for flights on a wealthy pal’s private jet after the press started sniffing around, according to documents introduced at his corruption trial on Thursday.

Department of Justice prosecutors on Thursday showed a Newark federal jury a $58,500 check Menendez paid his good friend, Dr. Salomon Melgen, for two round-trip flights he took in 2010 on the wealthy eye doctor’s private jet.

Prosecutors made a point, however, of noting that the check was written in Jan. 2013 — following a 2012 inquiry from a Washington Post reporter about those very same flights.

“The check was written after” the reporter started asking questions, FBI agent Christina Cobb said in response to a prosecutors questions about the timing of the check.

A separate document showed that Menendez was also only billed for the 2010 flights by Melgen’s son-in-law after newspaper’s Nov. 2012 inquiry.

Menendez, 63, is on trial in Newark federal court for accepting bribes — including all-expense-paid trips, private jet excursions and $750,00 in campaign contributions — from the wealthy West palm Beach opthalmologist, who was convicted earlier this year of Medicare fraud. In exchange, Menendez helped the doctor with his business and personal needs, including a $8.9 million tab for over billing Medicare, according to prosecutors.

The documents cap off a week of explosive testimony from two of Melgen’s three foreign girlfriends who secured visas to visit the married doctor, 63, with help from Menendez. One of the girlfriends, Rosiell Polanco, described getting gold-star treatment from the US embassy in the Dominican Republic after Menendez told a staffer he would call the ambassador, personally, on her behalf.

Three pilots and other airline personnel also took the stand this week to say that Menendez accepted more than 20 flights from Melgen between 2006 and 2010, including 19 flights on his personal jet, an $800 commercial flight — and a private charter from Florida to Washington, DC, that cost Melgen more than $8,000.

On Thursday, pilot David Donovan took the witness stand to recall the time his boss, businessman Hank Asher, demanded he go to the Dominican Republic to pick up a group of people, including the senior senator from NJ.

Asher, who is now deceased, smuggled cocaine in the 1980s before becoming a tech millionaire, although he was never charged with any crime.

“He called me up and told me I had to pick up Dr. (Salomon) Melgen” from the Dominican Republic and return him to Florida, the pilot recalled. “He said there would be a senator on bard,” the pilot testified.

Asked why he remembers the flight, Donovan said “it was unusual. I wouldn’t typically fly high profile people.”

Menendez and Melgen have denied the allegations claiming that any gifts and favors exchanged were the result of their decades-long friendship, which started in the 1990s before Menendez was a US senator.