Speaking on Sanyuka Television on Tuesday, Munyagwa said the posthumous DNA exercise had reopened old wounds instead of preserving the late musician's legacy.
"I condemn whoever decided to conduct DNA tests on the late Paul Kafeero's children. Kafeero died after publicly acknowledging his children. If he had wanted DNA tests, he had the opportunity and the resources to do so while he was alive, but he did not," Munyagwa said.
His remarks come days after forensic experts from the Uganda Police Forensic Laboratory and the Government Analytical Laboratory announced that only four of the 25 people who claimed to be Kafeero's biological children were genetically linked to the late singer.
The findings followed the exhumation of Kafeero's remains as part of a long-running legal battle over his estate and are expected to play a key role in proceedings before the Mengo Chief Magistrate's Court.
The forensic analysis identified Benedicto Kafeero, Simon Peter Kafeero, Thomas Swaz Kafeero and Elizabeth Nagawa as Kafeero's biological children, while the remaining 21 claimants, including musician Deus Ndugwa, were excluded.
However, Munyagwa questioned both the necessity of the exercise and the certainty of the scientific conclusions.
"You should not subject someone to DNA testing after their death. If my wife tells me a child is mine, that is enough for me. I do not have to take the child for DNA testing," he said.
He also cast doubt on the possibility of errors in laboratory testing.
"DNA testing is done by human beings, and wherever human beings are involved, mistakes can happen. We have seen patients diagnosed with typhoid at one health facility, only to be told at another hospital that they have allergies instead. Scientists can reach different conclusions," he argued.
Munyagwa further questioned whether DNA extracted from Kafeero's exhumed remains could have deteriorated over time.
"How can anyone be certain that Kafeero's DNA had not degraded after all the years since his death? There could have been chemical weathering affecting the samples. How can you be sure the samples remained intact?" he asked.
He also pointed to what he described as contradictions between the forensic findings and physical resemblance.
"There are children who sing, speak and even resemble Kafeero, yet the results say they are not his children. Others who do not resemble him at all have been declared his biological children. We are not fools," Munyagwa said.
The release of the DNA findings has sparked a nationwide debate over inheritance, family identity and the role of forensic science in resolving long-standing succession disputes.
The case has also reignited calls for better estate planning and prompted wider discussions among political and legal leaders about the implications of expanded DNA testing in Uganda.