Free State Agricultural Union chairman Dr Piet Gouws gave this testimony before the commission's amnesty committee in Bloemfontein.
The committee was hearing an amnesty application from former police captain Jacobus Johannes du Ru, 42, for the murders of Jonas Ramphalile and Zacharia Mofokeng.
Du Ru is also implicated in several other killings. In earlier testimony, du Ru said his job was to execute black men suspected of killing farmers.
His method was to take suspects to deserted places, shoot them dead and claim they tried to escape.
Du Ru, once described by an attorney-general as the "judge, jury and executioner" of suspects, said his actions were influenced, supported and condoned by his superior officers.
The political objectives of his actions, he said, were the defence of the apartheid system and the suppression of the African National Congress.
Gouws was asked by the commission to sketch a background of the period 1989-1992, when farmers were subjected to a series of attacks and several were murdered.
It was during this period that du Ru performed his executions.
Gouws said an atmosphere of pychosis and fear prevailed in the farming community.
Farmers felt the attacks were politically motivated because of their sheer brutality and because mostly weapons were stolen in the attacks.
Harsh action against the perpetrators was supported by the farming community.
The general perception was that the Azanian Peoples Liberation Army specifically, and also Unkhonto we Sizwe, would try to drive farmers from their land, instil fear into the hearts of the farming community and disrupt the rural economy.
Gouws said he was incensed when a Vredefort woman, widowed in an attack, described her ordeal to him.
"I felt that if I could get hold of the people responsible, I would probably have committed a crime myself," he said.
When ministers like Kobie Ceotzee and Hernus Kriel told a public meeting the attacks were criminal and not political, he had to restrain farmers from physically assaulting Coetzee and Kriel.
"Psychosis prevailed and the insecurity of farmers was immense."
Farmers had a "direct working relationship" with the police and the army.
Asked whether many policemen were recruited from the farming community, Gouws said there was a time when Afrikaners were "poor whites".
"It was a tremendous honour to become a policeman. It was a way to get somewhere in life. The farming community was the recruitment ground for the police and the armed forces."
Gouws said the farming community was conservative and that there had not been much forgiveness and reconciliation among farmers.
Also applying for amnesty were four Pan Africanist Congress activists from Bothshabelo: Hendrik Leeuw, Meshack May, Sebolai Nkgwedi and Daniel Magoda.
Leeuw and May received the death sentence, later commuted, for the murder in February 1992 of farmer RJJ Fourie. The four men are serving lengthy sentences.
Truth commissioners appeared openly sceptical of their claim that the murder was politcally motivated.
They said they were part of a Pan Africanist Congress task force deployed to kill farmers in an attempt to regain the land taken from black Africans by white settlers.
The men stole watches, money, Kruger Rands, groceries, pocket knives, calculators, cameras, clothing and Fourie's car in the attack on his farm.
They said the items they stole were to be given to Apla commander Jan Shoba to sell and raise money for the liberation struggle.
Faced with questions from commissioners which bordered on sarcasm, Nkgwedi went on the offensive and called for the Truth Commission to be disbanded.
"Mandela must disband the TRC because it is being run by white thugs," he said.
Directing his statements at Judge Andrew Wilson in particular, Nkgwedi said "white thugs" had been assaulting and abusing blacks ever since they arrived in "Azania" in 1652.
Blacks were fighting to regain land stolen from them by whites.
"Our forefathers died as slaves. Whites have luxury houses while we have sheds. Compare the number of Africans killed by the Boers and vice versa. The remains of Africans are being exhumed on farms in the Free State."
The clearly unrepentant Nkgwedi was asked by the Truth Commission why he was applying for amnesty.
He replied: "The objective here is to publicise throughout the world that Africans had a role to play to fight the oppression of the white man.
"Nothing will remain a secret, it must come out in the open."
Another reason he applied for amnesty was to state publicly that blacks were being assaulted and murdered in Grootvlei and Leeuwkop prisons.
Judge Bernard Ngoepe said the Truth Commission would investigate his allegations.