The eight, part of a United Nations peacekeeping mission, were detained and confined to their barracks in the eastern city of Beni earlier this month.

"Due to the serious nature of the allegations, the SANDF took a decision to recall the implicated soldiers back to South Africa to answer to the allegations and to give account of events that transpired," the South African National Defence Force (SANDF) said.

Investigators have been dispatched to the DRC to conduct a formal probe, it added.

The soldiers may have been involved in what the UN mission in the Democratic Republic of Congo (MONUSCO) described in internal reports as a "systematic widespread violation" of UN rules.

Earlier this week, UN spokesman Stephane Dujarric said MONUSCO had received reports that the personnel involved "were fraternizing, after curfew hours, at an out-of-bounds bar known to be a place where transactional sex occurs".

UN military police officers who went to the premises to assess the situation "were physically assaulted and threatened by the contingent members," as they moved to detain the soldiers, he added.

The SANDF said it was "unfortunate" that Pretoria was not directly informed of the allegations but learnt about them from the media.

Since May, Congolese President Felix Tshisekedi has been calling on SADC (Southern African Development Community) countries, including South Africa, to deploy in the country in support of the Congolese army in the face of the M23 rebels, who have seized large swathes of North Kivu province.

Kinshasa has also been calling for an "accelerated" departure of the UN force from December, accusing it of having failed to put an end to violence by armed groups during its 25-year presence.