The Ukrainian opposition politician Viktor Medvedchuk has escaped house arrest, Ukrainian interior ministry adviser Anton Gerashchenko said on Sunday, though Medvedchuk's lawyer swiftly denied the allegation.
Medvedchuk, the leader of Ukraine's Opposition Platform - For Life party, had been under house arrest since last year after the authorities opened a treason case against him.
Medvedchuk, a pro-Russian figure who says Russian President Vladimir Putin is godfather to his daughter, denies wrongdoing.
Medvedchuk's lawyer said Medvedchuk had been forced to move location due to threats from nationalist groups and had informed the authorities about them.
"In connection with the real danger to life, as well as the need to ensure his protection, Viktor Medvedchuk was evacuated to a safe place in Kyiv," the lawyer Larysa Cherednychenko said.
Medvedchuk would continue to meet his legal obligations during the hearing of the treason case, she added.
Medvedchuk has been under house arrest since last May, facing accusations of treason and attempting to plunder state resources in Crimea, a part of Ukraine which Russia annexed in 2014.
His arrest riled the Kremlin last year and news of his possible escape comes as Russia unleashed a full-scale invasion of Ukraine. British intelligence believes Russia had intended to install a pro-Russian puppet government, a claim that the Kremlin has brushed off.