KYIV (Reuters) -Undisputed heavyweight world champion Oleksandr Usyk has been released after detention by law-enforcement officers at Poland's Krakow airport, Ukraine's President Volodymyr Zelenskiy said on Wednesday. "I was outraged by this attitude towards our citizen and champion," Zelenskiy said on the Telegram messaging app. It was not immediately clear why the 37-year-old Usyk was detained.