A five-step process of identification is underway on the bodies of the South Africans killed in the Nigeria church building collapse, Minister in the Presidency Jeff Radebe said on Wednesday.

Updating reporters in Pretoria on the situation, he said this was a "methodical and time consuming process, and one would not be able to predict the exact timeframes for completion".

Radebe said 62 of the 84 South Africans killed in the disaster had been identified "with certainty".

"On the issue of the bodies, right now, the team that is there in Lagos has been able to identify with certainty 62 South Africans.

"So the remainder, as you know there are 115 deceased in this tragedy, and 84 of the 115 are South Africans, so we still have a long time to go... ," he said, adding that he meant not long in terms of time, but in effort.

Government was committed to ensuring that all those killed were accurately identified, and their bodies brought home.

"We want to assure the South African nation that we shall spare neither strength nor effort in ensuring that the deceased are repatriated back home.

"We believe that the repatriation of the deceased is the crucial first step in helping the families find closure in the aftermath of this terrible tragedy."

Radebe, who heads an interministerial team tasked by President Jacob Zuma to manage the situation, said identification of bodies following a disaster was a specialised scientific process, involving painstakingly thorough procedures.

"A South African team of experts on the ground in Nigeria is working closely with [their Nigerian counterparts] to ensure that this process is completed as soon as possible."

The process involved either identification of bodies by next of kin, through photo identification, from fingerprints, from dental records, or - if all these were not possible - through DNA.

He said DNA sampling took time.

"Our government appeals to the families and the nation to bear with us as we allow our team in Lagos the necessary time to complete this process."

All efforts were being made to keep the identification process as short as possible.

Once the bodies were all identified, a team of 70 South African military health service experts "is ready to depart for Lagos with specialised equipment to transport the deceased back to South Africa with the required care and the required respect", Radebe said.

Around 115 people, among them 84 South Africans, were killed and dozens trapped when a multi-storey guesthouse attached to the Synagogue Church of All Nations collapsed in Lagos on September 12.