It was not immediately clear why the 37-year-old was detained.
Heavyweight boxing champion Oleksandr Usyk has been released after being briefly detained at Krakow Airport in Poland, Ukraine President Volodymyr Zelensky said.
“I was disappointed by this attitude towards our citizen and champion,” said Mr Zelensky after he had a phone conversation with Usyk.
“Our champion has been released, and he is no longer being detained.”
He posted a photo of Usyk with Ukraine’s Consul General in Krakow after the athlete was released.
It was not immediately clear why the 37-year-old was detained.
He is one of Ukraine’s most prominent athletes known abroad, and he has organised and participated in different projects aiding his country’s efforts to resist Russia’s invasion.
“A misunderstanding took place. It was quickly resolved,” said Usyk, expressing gratitude for the “efficient support” of Ukrainian diplomats.
“And respect to Polish Police for conducting their obligations with no regards to height, weight, reach and regalia,” he said on Instagram.
Andrii Sybiha, who was recently appointed Ukraine’s foreign minister, said on X that he was briefed on the details of Usyk’s detention.
“Such actions towards our champion are disproportionate and unacceptable,” he said. “We’ll send a relevant note to the Polish side.”
Usyk beat Tyson Fury in May in Saudi Arabia to become the first undisputed world heavyweight champion in 24 years.
Fury’s rematch with Usyk is scheduled for December 21, again in Saudi Arabia.