Johannesburg - Genetic testing to identify the remains of 84 South Africans killed in the Nigerian building collapse was extremely difficult, the Saturday Star reported in South Africa.
Dr Munro Marx, head of Stellenbosch University's Unistel Medical Laboratories genetic testing centre that conducted the testing, said it was "by far...most difficult matchings we have been expected to do".
"In the temperatures and humidity of Lagos, decomposition happens pretty fast," he told the newspaper.
Recovery of the bodies only began four or five days after the guest house belonging to the Synagogue Church Of All Nations in Lagos - headed by preacher TB Joshua - collapsed on 12 September, killing 116 people.
"So when they recovered the bodies they embalmed the bodies."
The chemicals used, however, penetrate tissues and bone meaning that "obtaining DNA is extremely difficult".
"The 116 samples that we got were really not at all of a good quality."
The samples were numbered, but to identify the remains, DNA samples needed to be taken from the victims' family members.
The state disaster management team, made up of health department and police officials, would be responsible for taking DNA from the families.
Marx described the task of the five geneticists working on the DNA tests as "extremely stressful".
"We were working almost around the clock every day".