Republican Pennsylvania Senate candidate Dr. Mehmet Oz may have violated federal law by failing to report a contract with Turkish Airlines, a complaint by an Armenian-American advocacy group alleges.

Oz filmed several promotional videos with Turkish Airlines, a firm owned in part by the Turkish government, in 2018 and 2021. The videos should have been enough to require Oz to register under the Foreign Agents Registration Act (FARA), according to the Armenian National Committee of America (ANCA), but he did not do so.

“Dr. Oz indisputably serves as public relations counsel, publicity agent, information service employee, or political consultant for Turkish Airlines,” ANCA writes to Assistant Attorney General Matthew Olson in a letter first reported on by the New York Post. “Dr. Oz offered advice to the passengers of Turkish Airlines as the airline flying to more countries than any other airline in the world, on healthy eating and exercises.”

The letter also notes that “Turkish Airlines has been a foreign principle since at least 1975 and as recently as 2015.”

BREAKING: ANCA calls on Department of Justice to investigate @DrOz for violating Foreign Agent Registration Act.

“Dr. Oz clearly serves as a foreign agent on behalf of the foreign principal @TurkishAirlines.”https://t.co/nWPwY0z9g6

— ANCA (@ANCA_DC) May 5, 2022

The Oz campaign denied any FARA violations in a statement to the New York Post.

“Other spokespeople for Turkish Airlines included Morgan Freeman and Ben Affleck. Like Dr. Oz, they were not required to register under FARA,” spokeswoman Brittany Yanick said. “This political hit is ridiculous. Individuals and firms working to advance the bona fide commercial interests of a foreign business are not subject to FARA and not required to register. DOJ has repeatedly recognized this longstanding exemption under the law including in several recent advisory opinions.”

FARA was passed in 1938 due to concerns of Nazi activities in the United States. It “requires certain agents of foreign principals who are engaged in political activities … to make periodic public disclosure of their relationship with the foreign principal, as well as activities, receipts and disbursements in support of those activities,” according to the Justice Department. (RELATED: ‘A Foreign Agent’: Here’s Why The Feds Raided Rudy Giuliani)

Oz is not the first politically-involved Republican to be accused of a FARA violation related to the government of Turkey in recent years. Former National Security Adviser Michael Flynn registered under the law in 2017 after his firm lobbied on behalf of a Dutch energy company owned by a Turkish businessman. Bijan Rafiekian, an executive at Flynn’s consulting firm, was found guilty of violating the law in 2019.

Born in Ohio, Oz has claimed to maintain dual citizenship to allow him to care for his elderly Turkish mother, who suffers from Alzheimer’s disease. Oz has pledged to give up his citizenship should he be elected to the U.S. Senate, as his chief opponent David McCormick and some experts have suggested that maintaining it makes the candidate susceptible to foreign influence.

Although he has denied political involvement in Turkey, a photograph of Oz voting in the 2018 Turkish election resurfaced in recent days. The photograph was initially posted to the Facebook page of the New York Turkish consulate, where Oz cast his ballot. A spokeswoman for the campaign claimed that Oz visited the consulate to discuss humanitarian work and was encouraged to vote while he was there. (RELATED: Dr. Oz’s Ties To Pharma, Tech Complicate Anti-Corporate Campaign Claims)

“Dr. Oz has already said when elected to the Senate he would renounce his citizenship. There is no security issue whatsoever, and David McCormick knows that he has maintained his dual citizenship to make it easier to help care for his mother who has Alzheimer’s and lives there,” Yanick said.

The 2018 Turkish presidential election was marred by a state of emergency, the exclusion of opposition media and “intimidation, harassment, and attacks aimed at opposition candidates.” This led international observers like Freedom House to conclude that the country’s political process is “not free.”

Former President Donald Trump endorsed Oz in April, citing his perceived electability in an important swing state.