Wealthy businessman Moise Katumbi – who has vowed to contest a presidential election at the end of the year – is being tried in absentia with six other people, including an American national, by the Supreme Court of Justice.
But at the opening of the trial, court president Judge Tuka Ilka said the proceedings were being postponed to October 10 on technical grounds.
“The summons (to appear) has irregularities with respect to Mr Moise Katumbi,” Ilka said.
Between 200 and 300 of Katumbi’s supporters gathered outside the court, where they lashed the trial as “harassment” and “political.”
Katumbi, 53, a former governor of the mineral-rich region of Katanga, has been living in self-imposed exile in Belgium since May 2016 after falling out politically with President Joseph Kabila.
The defendants are accused of recruiting and arming mercenaries, leading to charges of “harming domestic security”, according to a court document seen by AFP.
The trial is taking place in the runup to a presidential election on December 23 in one of Africa’s most volatile countries.
Kabila, a former soldier who has been in power since 2001, has refused to say clearly whether he intends to run again.
He was constitutionally due to quit office in December 2016 at the end of his second elected mandate.
But he has remained in power until a successor is elected, provoking street protests that have been violently repressed, resulting in several deaths.
Katumbi has declared he will return to the country to file his candidacy. The period for applications runs from July 24 to August 8.
However, he cannot return home without fear of arrest as he has been convicted in a separate case involving alleged property fraud. He was handed a three-year term – he denies any crime.
In the meantime, he has set up a political vehicle called Ensemble to push ahead with his presidential ambitions.
Katumbi’s lawyers sharply criticised the choice of the Supreme Court of Justice as the trial venue.
No appeals can be lodged against rulings by the court, which means the trial will “accelerate” any sentence against him, further blocking his presidential goal, said one of his lawyers, Papy Mbaki.
Observers believe the adjournment will advantage the accused as the timing comes when the incumbent, whose establishment is pushing the charges, will be facing the exit door in an election set for December 23.
Kabila is constitutionally barred from seeking re-election.