WASHINGTON (Reuters) - In a court case that could further strain American relations with Turkey and weigh on the sentencing of former U.S. national security adviser Michael Flynn, a criminal trial began on Monday involving a former Iranian-American business partner of Flynn.

FILE PHOTO: Former U.S. national security adviser Michael Flynn departs after his sentencing was delayed at U.S. District Court in Washington, U.S., December 18, 2018. REUTERS/Joshua Roberts/File Photo

Bijan Rafiekian’s trial in U.S. District Court in Alexandria, Virginia, turns on whether he conspired to lobby on Turkey’s behalf to try to persuade the U.S. government to extradite Muslim cleric Fethullah Gulen, blamed by Turkey for a failed coup in July 2016.

“During the summer and fall of 2016, the defendant has acted as an agent to advance one of Turkey’s most important foreign policy goals,” one U.S. prosecutor said in his opening statement, adding that was to help support Ankara’s goal in seeking the extradition of Gulen from the United States.

Flynn, a retired U.S. Army lieutenant general whose brief tenure in 2017 as part of President Donald Trump’s inner circle is still causing legal aftershocks, is not charged as a co-conspirator with Rafiekian. But the case could influence how U.S. District Court Judge Emmet Sullivan sentences Flynn later this year in Washington.

Flynn had previously agreed to cooperate with U.S. prosecutors and testify against Rafiekian, known as “Kian,” in hopes of getting a lighter sentence after he pleaded guilty in December 2017 to having lied to Special Counsel Robert Mueller’s investigators about his contacts with Russian officials.

In a reversal earlier this month, Flynn and prosecutors had a falling out and Flynn backed away from earlier admissions of making false statements to the U.S. Justice Department in paperwork that disclosed his work as a Turkish government lobbyist.

Flynn now contends he relied on attorneys’ advice when filing the lobbying paperwork with the Justice Department and that he did not knowingly file false information.

STRAINED TIES

Rafiekian faces two criminal counts of conspiring to act as an agent of a foreign government, making false statements to the Justice Department and acting as a foreign agent. His former client, Turkish-Dutch national Ekim Alptekin, is also charged.

The trial, which began on the third anniversary of Turkey’s failed coup that killed 251 people and wounded more than 1,500, has implications for already strained ties between Ankara and Washington.

U.S. prosecutors are aiming to build a case showing Rafiekian and Alptekin acted with direction from the Turkish government and did not disclose their lobbying campaign to return Gulen, a shadowy figure who lives in a fortified compound in Pennsylvania, to Turkey.

The Turkish government has denied engaging in a conspiracy to evade U.S. regulations requiring foreign government lobbyists to register with the Justice Department.

“The idea that we would conspire against the United States is preposterous. ... We categorically reject any accusation of wrongdoing or illegal conduct in the United States,” Fahrettin Altun, spokesman for the Turkish presidency, said in a statement over the weekend.

Lawyers for Rafiekian denied the allegations. “Bijan never conspired with anyone, never ever sought to avoid U.S. regulations, never conspired to serve as an agent of a foreign government,” his attorney, Bob Trout, said in his opening statements.

Government lawyers now no longer plan to call Flynn as a star witness in the Rafiekian case, although they may end up calling Flynn’s son, Michael G. Flynn, who worked for Flynn’s lobbying firm, known as the Flynn Intel Group. Defense lawyers for Rafiekian have listed the elder Flynn as a possible star witness in the case.

The U.S. government is expected to call five witnesses on Tuesday, prosecutors said. Michael G. Flynn was not one of them.

Flynn was due to be sentenced in December 2018, but his sentence was delayed after Judge Sullivan lambasted him for selling his country out to Russia and urged him to complete his cooperation with government prosecutors.