A senior Pretoria advocate was asked to apologise for his stint in the Conservative Party and defence of apartheid-era perpetrators as the Judicial Service Commission interviewed nominees for judges on Monday.

Advocate Hennie de Vos readily conceded during questioning that he was chairman of the Waterkloof branch of the far-right CP from 1982 to 1987.

He denied that the party believed black people were inferior to whites, and said he left the National Party for the breakaway CP in a "dispute between Afrikaners" about the tricameral parliament.

De Vos said he had not been involved in politics for 22 years.

For years he had taken in black law graduates as trainees because he believed it was the best way of transforming the judiciary.

But advocate Dumisa Ntsebeza, one of President Jacob Zuma's new appointees to the JSC, said De Vos had failed to explain his conversion from right-winger to a promoter of racial parity on the bench.

"I would be a happier person if you are ready to say: 'I'm a person who was part of a bad past.' I do not get that sense from you," he said.

De Vos conceded that during the liberation struggle, he believed the ANC was preparing a full-scale war and that the prospect "scared" him. He had, however, broken with the past and denied having been a racist, saying: "I have always treated everybody on an equal basis."

To this, the JSC's advocate Marumo Moerane interjected: "Some of your best friends are black?"

De Vos responded: "I have a lot of black friends. I also have some white friends."

Inkatha Freedom Party chief whip and former CP colleague Koos van der Merwe came to De Vos's defence.

"He's a model advocate in terms of transformation and I know it comes from his heart," he said.

The JSC interviewed 10 nominees for six vacant positions at the Gauteng High Court.

The interviews began days after Zuma's nominees to the JSC were appointed.

On Tuesday, the JSC will interview nominees for the Western Cape and Eastern Cape divisions.