A senior official at the Japanese Olympic Committee (JOC) jumped in front of an underground train in an apparent suicide on Monday morning, private broadcaster Nippon Television said, citing Tokyo metropolitan police sources.
The police are investigating the details surrounding the death of the official, Yasushi Moriya, 52, the television network said. The JOC is gathering information on the incident, a committee representative told Reuters.
The death comes amid growing resistance to the Olympics.
At parliament, opposition lawmakers on Monday grilled Prime Minister Yoshihide Suga and cabinet ministers over going ahead with the Games despite worries that holding such a big sporting event could further spread coronavirus infections.
Japan has been "cornered" into holding the Games despite public opposition during the pandemic, one of Japan's sporting heroes and a member of the local Olympic committee said earlier.
Top government officials repeatedly said that the government would continue to work on coronavirus measures for a "safe and secure" Games, and that a decision on domestic spectators would be made this month.
"Taking infection control measures for athletes and Games officials so athletes from the world can safely participate and to protect our people's lives and health, I think that is the premise of holding (the Olympics)," Suga told lawmakers.
In a Yomiuri survey conducted June 4-6, 50 per cent of respondents said the Games would happen this summer; 26 per cent said they would occur without spectators. That is higher than 48 per cent of those polled saying the event would be cancelled.
But most of the respondents in the same poll said virus measures for Olympics athletes and participants are not enough, while public support for the Suga administration hit their lowest level, at 37 per cent.
About 3,500 out of over 40,000 "city volunteers" recruited by regional governments for the Olympics have pulled out, NHK reported. That adds to 10,000 volunteers had already withdrawn, according to the organisers.