The Freedom Front Plus said the state's failure to release Clive Derby-Lewis on medical parole, as it did with Schabir Shaik, was a severe case of double standards that undermined the government's credibility.

"While Schabir Shaik plays golf on medical parole, Clive Derby-Lewis is receiving chemotherapy for serious prostate cancer," FF Plus leader Pieter Mulder said yesterday in a statement.

"According to correctional services, Derby-Lewis apparently does not qualify for similar medical parole. No logical or legal explanation exists for these double standards, which seriously affect the credibility of the department of correctional services and the relevant ANC ministers," Mulder said.

He said it appeared authorities were dragging their feet processing Derby-Lewis' latest application for medical parole.

"Clive Derby-Lewis is 75 and his life expectancy is less than 24 months if the cancer is not effectively fought off by the chemotherapy. He qualifies according to all guidelines for medical and normal parole.

"He should have been granted parole in October 2008, on the basis of his age and according to recommendations of his parole board.

"The process was sunk numerous times by politicians. It appears as if his new application is also calculatingly being held up."

Derby-Lewis was sentenced to life in prison for his role in the 1993 assassination of Chris Hani, general secretary of the SACP and leader of the ANC's military wing.

Political parties have urged the ministry of correctional services to review Shaik's parole conditions after he allegedly hit a journalist from the Sunday Tribune.