Former Czech Republic defender Frantisek Rajtoral, who won the domestic league title four times before joining Turkish club Gaziantepspor, died on Sunday. He was 31.
The Czech football federation said in a statement that Rajtoral had "committed suicide in Turkey."
His agent Pavel Zika confirmed the player's death, describing it as a "huge tragedy."
Gaziantepspor announced Rajtoral's death in a brief statement on its website.
“Unfortunately I can confirm that the news of suicide is true,” Gaziantepspor president Ibrahim Kizil said.
“His team-mates were concerned after Rajtoral didn’t participate in today’s training session. He had good spirits, he didn’t seem to have any problem. I really don’t know why he did such a thing.”
Rajtoral played 14 international matches for the Czech Republic.
In the top Czech league, he won four titles with Viktoria Plzen and played in the group stage of the Champions League twice for the club. He moved to Hannover in the Bundesliga in 2014 for half of the season, on loan.
He left Viktoria Plzen last year to move to Turkey.