The death occurred while Ovchinnikov was attending a training camp with the Dynamo Moscow volleyball club team in Croatia, according to Reuters. Reuters added that the team's website reported he "suddenly passed away."
According to RT.com, Ovchinnikov allegedly committed suicide, possibly in response to his teams 5th place finish in the Olympics.
Russia was one of the favorites to win, but was pushed out of medal contention by Brazil.
RT reported, via RSN, that former Russian coach Vladimir Kuzyutkin told media that he didn't "know why he couldn't cope" with the loss.
According to InsideTheGames.biz, Alexander Yaremenko, the general director of the All-Russian Volleyball Federation Alexander Yaremenko couldn't confirm the suicide reports, but did confirm that Ovchinnikov was dead - and that "so far nothing's clear."
The last high-profile Olympic suicide to hit the US news occurred in July 2011, when Idaho freestyle skier and Olympic silver medalist Jeret "Speedy" Peterson killed himself outside Salt Lake City.