Teddy Williams, also known as Wellington Sejake, told the commission's hearings in Umtata that he had been sent to Quibaxe camp in Angola in 1978 as a commander, after receiving military training in the former Soviet Union.
There he witnessed officers "helping themselves" to women recruits.
"These young girls were abused by the officers, mostly the administrators. They used to call them to administration and then do what they wanted.
"Some of the trainees came with their girlfriends and wives. Even those wives were abused."
Williams said when he protested against the officers' behaviour, he was removed from his post and demoted. He was sent to Kamalunga training camp in 1980 as a military engineering instructor.
The ANC leadership had ignored complaints about corruption in the camps, and recruits' grumbles about fighting Unita instead of being sent back to South Africa, he said.
"When Chris Hani was appointed army commissar, we thought here is someone who will listen to us. But we were never given a chance to speak to him. We were always told he was in a hurry."
Williams said when some cadres refused to go into battle against Unita, MK commander Joe Modise, now Defence Minister, told them they were "half-baked" soldiers.
However, the protests continued, eventually swelling into a munity which swept through a number of ANC camps in Angola. After the mutiny was quelled, Williams said he was taken to Quatro training camp for "reorientation".
William's attempts to give details of the mutiny were repeatedly interrupted by commission member Ntsiki Sandi, who told him to concentrate his testimony on the abuses he had suffered at the hands of the ANC.
When Williams ignored this instruction and continued to give evidence on the mutiny, his microphone was switched off and he was again told to concentrate on his ill-treatment.
Williams said the ANC should be made to "cleanse itself" by compiling a list of names of people who had died in exile and giving the reasons for their deaths.
"As a Truth Commission we are interested in the truth and would have failed in our brief if we did not find the truth," commissioner Bongani Finca told him afterwards.