FILE PHOTO: Turkish NBA player Enes Kanter speaks about the revocation of his Turkish passport and return to the United States at National Basketball Players Association headquarters in New York, U.S., May 22, 2017. REUTERS/Lucas Jackson

ISTANBUL (Reuters) - The father of U.S.-based Turkish basketball star Enes Kanter has been detained in Turkey in an investigation targeting supporters of the cleric whom Ankara accuses of orchestrating last July’s failed coup, state-run Anadolu news agency said on Friday.

It said Mehmet Kanter, a university professor, was detained at his home in the Kadikoy district on the Asian side of Istanbul. Police were not immediately available to comment.

Kanter, who plays for the National Basketball Association’s Oklahoma City Thunder, is a long-time supporter of Pennsylvania-based preacher Fethullah Gulen, whose extradition Turkey’s President Tayyip Erdogan is seeking in relation to the putsch.

Kanter was detained in Romania on May 20 when authorities learned his Turkish passport had been revoked. He subsequently returned to the United States.

The 6-foot-11-inch (2.11 meter) center, whose team was eliminated from the NBA playoffs, commented on his father’s detention on his Twitter account on Friday.

“Hey world. My dad has been arrested by Turkish government and the Hitler of our century,” he wrote, lashing out with the same expression he used to refer to Erdogan at a news conference in New York last month.

Last August, Kanter severed ties with his family and pledged allegiance to Gulen after Turkish media published a handwritten letter signed by Kanter’s father, disowning a son he accused of having been “hypnotized” by Gulen’s movement.

The family split came three weeks after rogue soldiers in tanks, warplanes and helicopters tried to seize power in Turkey in a putsch that killed over 240 people and wounded 2,200.

Gulen, who has lived in self-imposed exile in Pennsylvania since 1999, has denied involvement in the coup.