The athlete took refuge in the Polish embassy in Tokyo on Monday, a day after refusing her team's orders to board a flight home from the Olympic Games.
Warsaw has offered her a humanitarian visa.
International Olympic Committee spokesman Mark Adams told reporters the body had spoken to the athlete twice on Monday, that she was in a safe, secure place.
"We need to establish the full facts, we need to hear everyone involved, that obviously can take time. And in the meantime obviously our first concern is for the athlete," he said. "We are expecting, we have asked for a report from the [National Olympic Committee of Belarus] today. We requested it yesterday, we want it today," Adams said.
Tsimanouskaya, 24, had been due to compete in the women's 200 metre heats on Monday but said that on Sunday she was taken out of her room in the athletes' village and driven to the airport to board a flight home after criticising team officials.