Hendrik Jacobus Steyn, 34, testified before the commission's amnesty committee hearing in Durban how he killed Michael Mthetwa and Simon Msweli after they were arrested in a shoot-out with police.
A former detective warrant-officer, Steyn said he decided to kill the men after it became known that three policemen were killed in the shootout.
He said both Msweli and Mthetwa were African National Congress members and belonged to a gang conducting a "reign of terror" in the KwaZulu-Natal north coast region.
At the time, Steyn was an Inkatha Freedom Party supporter based with the Empangeni murder and robbery unit. He said he acted against the men because they were known criminals and his "political opponents".
On his way to the scene of the shoot-out on August 14, 1992, Steyn said he stopped a police bakkie with the two ANC men on the back. They had been wounded in the shoot-out and arrested.
The two men were taken off the bakkie and Styen shot them both dead with five shots fired from his R5 rifle.
He said he was congratulated by a senior police official minutes after the execution.
Steyn, who was arrested a few days later, was found guilty in December 1992 and sentenced to 18 years' imprisonment.
He is now applying for amnesty and says he regrets the deed.
His lawyer, Oliff d'Oliveira, said policemen were "required to do duties outside the normal scope of police work".
"At the time, policemen were used as a tool by the former goverment against their opponents. In the Kwambonambi area, there was a violent struggle between the ANC and the IFP," d'Oliveira said.
He submitted his client met the requirements set out in the Amnesty Act.
"This (the killing) was the result of abnormal policing. They were placed in a role not associated with police work," he said.
Commision lawyer Robin Brink said he believed the criminal activites of the two ANC men could be described as political and he believed they were relevant to Steyn's amnesty application.
Steyn's application would be considered by the amnesty committee.
The committee closed its Durban hearings on Wednesday. A commission spokesman said the next amnesty hearings would start in Mmabatho and Potchefstroom in North-West province on September 9, followed by hearings in Gauteng.