Delphin Kahimbi, 50, a close associate of former president Joseph Kabila, had died of a heart attack on February 28 at home in Kinshasa, his wife and media reports said.

But rumours abounded that he was killed or committed suicide.

Tshisekedi ordered a probe into the death, and the preliminary findings were made public on Saturday after a cabinet meeting.

"According to the evidence ... it turns out to be a hanging," a statement quoted the president as saying.

Tshisekedi said he wanted the probe to be wrapped up quickly to "bring relief to the bereaved family".

In recent days, Kahimbi was barred from foreign travel, stripped of his functions and questioned by the national security council, sources said earlier.

Kahimbi was under EU sanctions for rights violations during the Kabila regime.

Tshisekedi, a former opposition leader, rules the Democratic Republic of Congo in a coalition with Kabila's supporters who have a majority in parliament and in other state institutions.

However, several pro-Kabila figures have been given the boot or seen their powers considerably whittled.

Kahimbi wielded enormous power and influence during Kabila's long rule from 2001 to 2019.