Sen. Robert Menendez’s office reaffirmed Friday that the New Jersey Democrat welcomes any investigation of his conduct, including a newly reported grand jury probe.

“Every day, more evidence emerges that the false smears against Senator Menendez are nothing but an elaborate campaign orchestrated by Republican political operatives,” Menendez spokeswoman Tricia Enright said in an email. “As we have said all along, we welcome any review because Senator Menendez’s actions have always been appropriate, and we believe the facts will confirm that.”

The Washington Post reported late Thursday that a federal grand jury in Miami is looking into allegations of improper conduct in relation to Dr. Salomon Melgen, a South Florida ophthalmologist with a long-standing personal and political relationship with Menendez. That a grand jury would explore the matter should come as no surprise: The allegations against Menendez gained steam following a federal raid of Melgen’s office in West Palm Beach in what’s been reported as a Medicare fraud investigation.

Sources told the Post that Melgen’s records have already been subpoenaed as part of the effort, but Menendez himself has not yet been questioned.

The report cites three unnamed individuals familiar with the legal inquiry. Typically, the Senate Ethics Committee defers action until after federal criminal investigations may be completed. Lack of criminal prosecution in no way precludes the Ethics panel from issuing its own rebuke, however.

For instance, former Sen. John Ensign, R-Nev., did not face criminal penalties in a corruption scandal that involved an affair with a staffer and an attempt to secure employment for the husband of that staffer. That led the watchdog group Citizens for Responsibility and Ethics in Washington to question the veracity of the Justice Department’s efforts in that case. Ensign resigned from the Senate after it became clear that the Ethics Committee was going to recommend severe punishment.

Menendez has conceded one least one error that the Ethics Committee is aware of. Menendez has conceded he did not report trips to the Dominican Republic with Melgen aboard a private plane. The senator cut a check to Melgen for $58,500 in January to cover the cost, although Menendez aides have said they believe that he could have claimed a personal relationship exemption from the Ethics panel.

Menendez and his advisers have pushed back hard against allegations that the senator engaged in prostitution during travel to the Dominican Republic. Multiple media outlets have reported on issues casting serious doubt on the legitimacy of the most salacious of the allegations against Menendez.