Istanbul (dpa) - A US official based in Turkey for the Federal Bureau of Investigations (FBI) has been summoned to the country‘s security service‘s headquarters, the state-run Anadolu news agency reported Wednesday from Ankara.The report said the official was summoned in connection with the ongoing trial in New York of a Turkish banker who allegedly helped Iran skirt US sanctions. During the hearing on Tuesday, a witness testified that he received financial assistance from the FBI, the report noted.The witness, a former Turkish police officer, appears to have removed evidence related to the case from Turkey. Ankara has accused the former officer of having links to Fethullah Gulen, a preacher the Turkish government blames for last year‘s coup attempt.