Testifying before the committee in Mafikeng, Sergeant Bernstein Menyatswe, who was then a constable, said he killed Alwyn Wolfaardt, Fanie Uys and Nico Fourie to defend the former bantustan nation.
He said during the invasion on March 10, 1994, the AWB members killed and injured many defenceless people. Addressing AWB leader Eugene Terre'Blanche, he said this angered and hurt him so much that he felt he "had to defend them against your soldiers Mr Terre'Blanche".
Menyatswe said while he was driving around Mafikeng he saw AWB members shooting randomly at people. Upon arrival at the police headquarters, he found a large group of terrified people who came to ask for police protection.
"I shot your soldiers because they brought war to Mafikeng," he said.
He asked the families of the slain AWB men to forgive him for the pain his actions had caused them. "It was a war situation... and I had nothing else to do but to shoot them as one of your men threatened to kill me."
Menyatswe asked Terre'Blanche to pardon him "because I shot your soldiers in a war situation", repeatedly stressing that the AWB members had angered him by trying to protect former Bophuthatswana president Lucas Mangope.
Mangope was preventing Bophuthatswana's people from taking part in South Africa's first all-race election.
Menyatswe further asked the family of his former colleague, Philemon Nare, who was blamed for the murder of the AWB men, to forgive him.
"I'm here today to tell the whole world that Nare did not kill your soldiers... He has suffered due to my action and was even suspended from police duty, and I ask him to forgive me."
During cross-examination by Terre'Blanche, he stressed that the three members were killed because they were a threat to the people of the former homeland.
Asked why he shot them while they had already been disarmed, Menyatswe replied: "As far as I'm concerned, they were armed and I saw them shoot one person next to me. When I approached them, one of your soldiers moved his hands and I thought he was pulling his gun.
"I shot them all at once in protection of the defenceless people."
The hearing continues.