Updated

Turkey's state news agency says prosecutors have launched an investigation into the U.S. attorneys trying a Turkish-Iranian businessman for sanctions-busting.

The Istanbul prosecutor's office on Saturday announced the investigation into ex-U.S. Attorney Preet Bharara and U.S. Attorney Joon H. Kim. Its statement, published by Anadolu, said the source of the documents and tapes being used as evidence in the U.S. case were unknown and violated international and domestic laws.

Gold trader Reza Zarrab, 34, has been charged in the U.S. for evading sanctions on Iran. An executive of Turkey's state-owned Halkbank and a former Turkish economy minister have also been indicted.

Turkish officials have accused Bharara of links to U.S.-based Muslim cleric Fethullah Gulen, whom Turkey blames for last summer's failed coup. Gulen denies the allegations.