The three - Petros Thulo, Roland Petrus and Paseka Mpondo - were jailed for killing members of the notorious Three Million Gang which terrorised Maokeng township outside Kroonstad in the late 1980s and early 1990s.
The gang was allegedly responsible for a series of brutal murders, rapes and attacks on ANC activists.
The amnesty committee heard on Tuesday how Maokeng's SDU had revenged the attacks by killing between 20 and 25 members of the gang over a period of several years.
One of the last to die was gang leader George Ramasimong, who was shot dead, execution-style, by Petrus near the town's taxi rank in 1992.
Petrus told the committee the community had met several days before the murder and decided that Ramasimong should be "removed from society".
Bloem, Petrus' cousin, was a co-accused at his trial and was fined R7500 or 18 months' imprisonment. The community paid the fine.
Bloem was one of the architects of the community's resistance against the gang, which allegedly operated in tandem with the police and the town council.
When he testifies on Wednesday, Bloem is expected to make a plea for the release of the former ANC Youth League members from Kroonstad prison, and to describe the political situation in the township at the height of the gang's reign of terror.
The attorney representing the three applicants, Vincent Matsepe, told Sapa he had intended putting a former member of the Three Million Gang on the stand on Wednesday to lift the lid on the gang's activities and the extent of its relationship with the police and the council.
However, Matsepe said he had been informed that police had arrested his witness on Tuesday.
He said he was "disturbed" by the timing of the man's arrest and intended raising the issue with the amnesty committee at Wednesday's hearings.
The committee is also scheduled to hear the application of ANC member Molefi Tshukudu, who was sentenced to 14 years' imprisonment in 1993 for the murder of Kroonstad resident Hannes Grobbelaar.
In his amnesty application, Tshukudu says he murdered Grobbelaar with a pair of sheep shears to convince the government to abolish the apartheid system.
He said he wanted equal rights for all South Africans "so that blacks can be recognised as citizens of South Africa in order for their say to be heard".