Belarusian authorities have detained prominent businessman Yury Chizh on suspicion of large-scale tax evasion.
Chizh had been a close adviser to Belarusian President Alyaksandr Lukashenka since the 1990s but had reportedly fell out of favor in recent months.
If convicted, Chizh faces up to seven years in prison.
Chizh, owner of the Belarusian firm Triple, was detained by the KGB, the Belarusian security service.
Dmitry Pobyarzhin, a representative of the KGB, said Chizh was in a "KGB detention center."
In 2012, Chizh was included on a list of European Union sanctions imposed on Belarusian individuals and companies in response to the country's human rights violations.
The EU ended five years of sanctions against Belarus and Lukashenka in February, citing improving human rights.