Sergey Ovchinnikov, 43, was at a training camp with volleyball team Dynamo Moscow, local media reported.

Speculation is rife that the alleged suicide was sparked by the national team's failure at the Olympics. Russia's women's volleyball team had started out as favourites at the Games but were knocked out in the quarter-finals.

The head coach of the men's team, Vladimir Alekno, is reported to have told RT.com that Ovchinnikov was devastated by the team's poor performance.

"He took the Olympics very personally," Alekno apparently said. "I saw what he was going through and how upset he was after the defeat."

Russian Volleyball Federation director general Aleksandr Yeremenko confirmed the death of Ovchinnikov, but  gave no further details, including whether or not it had been a suicide.

"Sergei Ovchinnikov suddenly passed away at the team's training camp in Croatia,"Yeremenko said.

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