The head of Ukraine's tax and customs service, Roman Nasirov, is being investigated over the suspected embezzlement of around 2 billion hryvnias ($75 million), his lawyer said on Friday.
Television footage showed Nasirov being stretchered into an ambulance late on Thursday. Reporters said he had suffered a heart attack. This could not be independently verified.
If Nasirov is accused and found guilty, it would be the first successful prosecution of a senior official for graft since the 2014 uprising that led to the installation of a Western-backed leadership that promised to root out endemic corruption.
"The sentence (would be) from three to six years in prison," lawyer Andriy Kuzmenko said, speaking on television channel 112.
Ukraine's anti-corruption bureau confirmed that there was a graft investigation against Nasirov, without giving further details.