Congolese presidential hopeful Moise Katumbi has been sentenced in absentia to 36 months in prison.
The wealthy businessman, who owns one of Africa's biggest football clubs, is currently out of Democratic Republic Congo seeking medical treatment.
The 51-year-old was found guilty of illegally selling a property in Lubumbashi, his eastern power base.
He had the backing of seven opposition parties to run for the presidency in elections due to be held in November.
President Joseph Kabila, in power since 2001, is nearing the end of his second term and he is constitutionally obliged to step down by December.
But there is growing political tension as it is not clear if he will relinquish power.
The court in Lubumbashi, DR Congo's second city, also fined the football tycoon $6m (£4.1m) for illegally selling the property, which a Greek citizen claimed belonged to his family.
Katumbi flew out of the country on 20 May, a day after the authorities issued an arrest warrant for him on separate charges of hiring foreign mercenaries - allegations he denies.
The BBC's Poly Muzalia in the capital, Kinshasa, says Katumbi's legal team is likely to appeal against the verdict.
Who is Moise Katumbi?
Moise Katumbi was governor of the south-eastern Katanga province for almost a decade.
In September last year he broke ties with the ruling party when he accused President Kabila, his former ally, of wanting to cling to power.
His popularity is partly down to his job as the president of a great source of Congolese pride - football club TP Mazembe.
They are Africa's reigning football champions, having won the African Champions League for the fifth time in November.