Investigators in the Democratic Republic of Congo have “serious evidence” pointing to actions against national security, the presidential spokesman has said.
In a statement read on state television on Tuesday night, Kasongo Mwema said such an attempt to “destabilise democratic institutions” would not be tolerated.
It follows the arrest on Saturday of François Beya, the special security adviser to President Félix Tshisekedi.
It happened as the president was attending an African Union (AU) summit in the Ethiopian capital, Addis Ababa.
The arrest triggered protests, with members of the president’s party taking to the streets.
On Tuesday, the president’s spokesman said investigations were ongoing and the situation was under control.
Silence from the government and the presidency since Saturday has fuelled speculation about instability in the country.
Neither Mr Beya nor his lawyers have made any public statement in reaction to the arrest.