Authorities in Congo have sentenced opposition presidential candidate Moise Katumbi to three years in prison in absentia.

Katumbi's supporters have decried his sentence as a political move aimed at stopping him from running in the presidential election set for November.

Mukendi wa Mulumba, one of Katumbi's lawyers, said Thursday that his client's sentence violated international law.

The sentence handed down Wednesday along with a $1 million fine relates to allegations that Katumbi falsely acquired a building.

In a separate case, authorities have issued a warrant for his arrest on charges he had hired mercenaries to protect him.

Following that warrant, Katumbi left the country for medical treatment — first to South Africa, then to Europe — and has not returned to Congo since.