TOKYO, Aug 4 (Reuters) - Belarusian sprinter Krystsina Tsimanouskaya arrived at a Tokyo airport early on Wednesday after leaving the Polish embassy, where she had taken refuge in a dramatic diplomatic twist at the Tokyo Olympics. Her refusal to board a flight home late on Sunday, after she said she was taken by her team to the airport against her wishes, caused high drama at the Games. She sought protection at at the embassy on Monday. She was expected to go to Poland, her supporters have said. Warsaw has offered her a humanitarian visa. read more Tsimanouskaya, masked and wearing blue jeans, a blue blouse and sunglasses, arrived in a police-escorted van at Narita airport east of the Japanese capital at 8:27 a.m. (2327 GMT on Tuesday) and did not talk to waiting reporters. The International Olympic Committee said on Tuesday it had launched a formal investigation into Tsimanouskaya"s case and was expecting a report from the Belarusian team. read more U.S. Secretary of State Antony Blinken accused Belarus President Alexander Lukashenko"s regime of intolerable "transnational repression" in the matter. read more Tsimanouskaya, 24, had been due to compete in the women"s 200 metre heats on Monday but said the Belarusian head coach had turned up at her room on Sunday at the athletes" village and told her she had to leave after she had criticised team officials. "I will not return to Belarus," she told Reuters at the time. The incident has focussed attention on Belarus, where police have cracked down on dissent following a wave of protests triggered by an election last year which the opposition says was rigged to keep Lukashenko in power. Belarusian authorities have characterised anti-government protesters as criminals or violent revolutionaries backed by the West, and described the actions of their own law enforcement agencies as appropriate and necessary. Vitaly Shishov, a Belarusian activist living in exile in Ukraine, was found hanged in a park near his home in Kyiv early on Tuesday, and Ukrainian police launched a murder investigation. He led an organisation that helps Belarusians fleeing persecution. read more