Turkish lawyer Burak Mengü was detained by a group of plainclothes police officers who battered him under custody, he revealed after being abandoned at a roadside in Istanbul’s Umraniye.

“No one told me why and where I was being taken to,” Mengü tweeted Saturday.

Meanwhile his sister, Nevsin Mengu said: “A group of people, claimed to be police officers, grab a lawyer in the middle of the day. When reactions grow, he was released after being battered. Is there a clique or a structure within the police department that acts illegally?”

“The police chief told me that there was no arrest warrant and that he will investigate this personally,” she said later.

Şahin Mengü, their father and a former Republican Peoples’ Party (CHP) deputy told the Özgürüz online news outlet on Saturday: “He will file a complaint about the incident. He was beaten up.”