Olga Safronova was barred from competing in the Tokyo Olympics after criticising state authorities over the health of one of her horses.
Poland has given a humanitarian visa to a second Belarusian athlete after they criticised state authorities.
Dressage rider Olga Safronova was excluded from the Belarusian team before this summer's Tokyo Olympics.
She has now been granted refuge in Poland, according to opposition lawmaker Joanna Kluzik-Rostkowska.
Safronova intends to train and compete with Poland’s national equestrian team, Kluzik-Rostkowska added on Sunday.
Before the Olympics, she had made angry comments about the authoritarian regime of Belarus President Alexander Lukashenko while in Poland.
Her anger related to one of her horses, which Belarus said was limping and unfit for competition. Veterinarians in Poland found no problem with the horse.
"When I arrived in Poland and had the horse examined, it was in perfect health and fit to compete," Safronova told the Polish news agency PAP.
The dressage rider then said that she had been added to a list of people considered traitors of Belarus.
"If you end up on this list, you cannot work or pursue your sports career," Safronova said. "If I had not left Belarus, it would have been dangerous for me."
After she was barred from competing in Japan. Safronova decided to seek refuge in Poland with her husband, and in mid-August they were issued humanitarian visas by Poland’s consulate in Lviv, Ukraine, Kluzik-Rostkowska told AP. Three of her horses have also been brought to Poland.
Last month Belarusian Olympic sprinter Krystsina Tsimanouskaya also found shelter in Poland to avoid punishment at home after she criticised team officials at the Tokyo Olympics.
Tsimanouskaya sought help from Japanese police at Tokyo airport to prevent Belarusian authorities from sending her home.
She eventually made her way to Poland, which issued her a humanitarian visa.
Poland has also offered refuge to Belarus dissidents and critics of Lukashenko who are fleeing reprisals, following his crackdown on opposition protests and independent media.