Czech Republic international Frantisek Rajtoral has committed suicide at the age of 31, the country's football association has confirmed.
Midfielder Rajtoral made 19 appearances for the Super Lig side after completing a switch from Viktoria Plzen, where he won four Czech First League titles in eight seasons.
He made 14 appearances for the Czech Republic and was a member of their squad for Euro 2012, during which he played twice.
The Czech Republic Football Association confirmed the news in a statement in which it expressed "its deepest condolences to all relatives".
Gaziantepspor president Levent Kizil was quoted by Sporx: "Unfortunately I can confirm that the news of suicide is true.
"His team-mates were concerned after Rajtoral didn't participate in today's training session. He was a proper person with good spirits. He didn't seem to have any problem. I really don't know why he did such a thing."