The player has already left Prague, but the organisers did not disclose her name to journalists today.
The organisers have informed all other registered Russian and Belarusian players of the situation via the WTA and do not expect any of them to take part in the tournament.
There is a ban on Russian and Belarusian athletes in the Czech Republic due to the Russian invasion of Ukraine.
Belarusian Aliaksandra Sasnovich was set to feature in the main singles stage of the tournament. Russians Diana Shnaider, Polina Kudermetova and Erika Andreeva were to enter the singles qualification.
Another Russian, Evgeniya Rodina, withdrew from the main event earlier due to injury.
"Yesterday in the early evening, officers of the Inspectorate of Foreigners' Police at the Vaclav Havel Airport carried out a residence check on a person of Russian nationality, during which the reasons for the termination of the temporary stay on the territory were established. The person was granted an exit order and given a deadline to leave the Czech Republic," the tournament organisers quoted a police statement.
"This was the first participant in the tournament to arrive in the Czech Republic with a Russian passport. At the moment she is no longer in the Czech Republic," said Miroslav Maly, the tournament director.
Maly assumes that none of the Russian or Belarusian tennis players will compete in the tournament after one of the players was not allowed to enter the Czech Republic. The official starting list will be published just before the draw. Qualification starts on Saturday, and the main competition on Monday.
"We immediately informed all other participants of the tournament with Russian or Belarusian citizenship about the situation through the WTA. They have been told not to travel to the upcoming tournament. We do not expect any player with Russian or Belarusian citizenship to participate in the upcoming tournament under this situation," said Maly.
Because of the Russian invasion of Ukraine, the government in June approved a ban on Russian and Belarusian athletes from competing on Czech territory. Although Belarus did not actively participate in the war, it allowed Russia to launch attacks from its territory.
A similar situation played out last week in Poland, where border guards refused to let Russia's Vera Zvonareva, who was due to take part in a tournament in Warsaw, into the country.
However, Belarus' Sasnovich and Yuliya Hatouka and Russia's Valeria Savinykh were allowed to enter the competition. The Russian and Belarusian players play in tennis tournaments under a neutral flag and without national symbols.
