A Florida doctor who is a major political donor of Sen. Robert Menendez may be charged as soon as this week for actions he allegedly took involving the lawmaker.

Federal investigators have been looking into dealings that Dr. Salomon Melgen, 59, had with Menendez, who has described the physician as a good friend.

The probe is centered in whether Menendez, a New Jersey Democrat, abused his office by taking actions to benefit the doctor, who in turn allegedly provided Menendez with flights to and from the Dominican Republic on his luxury jet.

The alleged actions by Menendez include becoming involved in a dispute on Medicare billing that involved the doctor.

Citing an unnamed person described as being familiar with a Justice Department investigation into their dealings, the Associated Press reported the pending charges against the Florida-based eye doctor.

Melgen has not been cooperating with prosecutors against Menendez, according to the person, who was not authorized to comment on the record about an ongoing federal investigation.

Melgen and his family have donated about $1 million to Menendez campaigns and committees on which he served.

Justice Department spokesman Peter Carr declined to comment Monday.

Menendez could also be charged soon, according to published reports that cited unnamed sources. The senator has repeatedly said that he has done nothing wrong and that he has always served honorably in Congress.

Menendez, the top Democrat on the Senate Foreign Relations Committee, joined the Senate in 2006 after serving more than a decade in the House of Representatives.

Under scrutiny, Menendez acknowledged in 2013 that he flew multiple times on Melgen's private jet to the Dominican Republic and initially failed to properly pay for the trips. Menendez agreed to reimburse Melgen $58,500. His office later disclosed a third flight, from Florida to New Jersey in 2011, saying he had repaid Melgen $11,250 for it.

Last week, VOXXI, a Latino-theme website that Melgen co-founded, shut down because of a failure to generate revenues and reach other goals, according to several published reports.

Among the things catching investigators’ eyes was Menendez’s reported advocacy for Melgen when he was accused of overbilling Medicare. Melgen was one of the top recipients of Medicare reimbursements at a time when he was contributing heavily to Democrats. He received $21 million in Medicare reimbursements in 2012 alone, according to The New York Times.

Investigators said that, for example, Melgen would get a vial of the medication, which would provide up to four times the amount that a patient requires. But Melgen, the investigators charged, used one vial to treat three or four patients, but then billed as if he had purchased a new vial each time.

Melgen then would be reimbursed $6,000 to $8,000 for a vial that cost him $2,000, The New York Times said. Investigators said that in in 2007 and 2008, for instance, he overbilled by $9 million, which he then paid back.

The Times said that federal authorities were alerted to the overbilling after a Medicare contractor noticed that Melgen was billing for Lucentis at a significantly higher rate than his peers.

And then there was Melgen’s concerns about the impact of a plan by the U.S. Customs and Border Protection agency to donate port screening equipment to the Dominican Republic. In a Senate subcommittee hearing in 2012, Menendez mentioned a company, which he did not name, that had a contract with the Dominican government to X-ray cargo at ports, but that the country’s authorities “don’t want to live by,” according to CNN.

Melgen had a company that stood to do X-rays of cargo passing through Dominican ports, and he apparently though that his business interests would be compromised by U.S. Customs and Border Protection equipment donations.

In January 2013, FBI agents swarmed Melgen’s Florida medical office and hauled off more than 30 boxes of evidence. FBI agents returned in October of that year, carrying boxes of documents out of the office.

Amid reports earlier this month of looming criminal charges, Menendez declared his innocence and said that he and Melgen had a close friendship dating back decades.

"We celebrated holidays together," he said. "We have been there for family weddings and sad times like funerals and have given each other birthday, holiday and wedding presents, just as friends do."

The Associated Press contributed to this report.

Like us on Facebook

Follow us on Twitter & Instagram