Belarusian sprinter Krystsina Tsimanouskaya took refuge in Poland on Wednesday after refusing to return to her authoritarian homeland from the Tokyo Olympics in a saga reminiscent of Cold War sporting defections.

The 24-year-old athlete's case could further isolate Belarusian President Alexander Lukashenko, who is under Western sanctions after a crackdown on opponents since last year.

Tsimanouskaya caused a furor on Sunday when she said coaches angry at her criticism had ordered her to pack and go to the airport. She refused to board a flight home and sought protection from Japanese police.

Poland, which has long been critical of Lukashenko and harbored many activists from Belarus, has granted her and her husband humanitarian visas.

"She needs to rest. She is tired but happy to be in Poland. She will stay in Poland in a safe place," Polish deputy foreign minister Marcin Przydacz told Reuters.

Some Belarusians waited at Warsaw airport, holding signs of resistance: carnations and flags in red-and-white.

"We are here to support our compatriot, who told the truth about what is happening in Belarusian sport," said Eugene Dudkin, 31, who left for Poland after being held for a night at a police station for protesting.

Warsaw-based Belarusian opposition politician Pavel Latushko tweeted a picture with Tsimanouskaya. "We hope that the agony of the regime will soon end, and Kristina will be able to return to conquering new sports peaks in the New Belarus!" he said.

The sprinter, who had criticized negligence by her team coaches, spent two nights in Poland's embassy in Japan before flying to Poland via the Vienna, Austrian.

She sported sunglasses with the words "I RUN CLEAN".

The Belarus National Olympic Committee (NOC) had said coaches withdrew Tsimanouskaya from the Games on doctors' advice about her emotional and psychological state. It had no further comment on Wednesday, nor did the government.

Sport plays a high profile role in Belarusian politics under Lukashenko, who personally headed the Belarus Olympic Committee until he was replaced by his son this year.

The International Olympic Committee has started an investigation into Tsimanouskaya's case and said it would hear from the two Belarusian officials allegedly involved.