"Belarusian citizen Vitaly Shishov [...] was today found hanged in one of the Kyiv parks, not far from where he lived," police said in a statement.
A murder probe has been opened, authorities said, adding that they would pursue all leads, including a possible "murder disguised as a suicide.".
The 26-year-old was the head of the Kyiv-based Belarusian House in Ukraine (BDU), an organization that helps Belarusians trying to flee persecution.
Opposition leader Sviatlana Tsikhanouskaya reacted to Shishov's death, tweeting that "it is worrying that those who flee Belarus still can't be safe.".
Police said Shishov was reported missing by his partner when he did not return from his morning run.
"There is no doubt that this was a planned operation by security operatives to liquidate a Belarusian dangerous for the regime.
Lukashenko and his son have been banned from Olympic events for targeting athletes who have openly expressed opposing political views. »
