South African national prosecutors have charged two of the most senior public security officials of the apartheid era with attempted murder.
Mr Vlok was in charge of security in South Africa during the late 1980s
Former Police Minister Adriaan Vlok and ex-police chief Johan van der Merwe are accused of plotting to kill a prominent opponent of apartheid in 1989.
Prosecutors said they and three others attempted to kill Rev Frank Chikane by lining his clothes with a nerve toxin.
Mr Vlok begged for forgiveness from Mr Chikane last year by washing his feet.
Mr Chikane, who is now director-general of President Thabo Mbeki's office, has called for others to come forward and reveal what happened, but has never called for prosecutions.
The National Prosecuting Authority (NPA) had until now been talking to lawyers of the two accused about how to proceed.
But a spokesman for the NPA, Panyaza Lesufi, said it had decided the case should be heard in an open court.
Rev Chikane has never called for prosecutions
"We decided that due to the nature of this case it can not be solved in a boardroom and it must be dealt with in the public domain," he told the South African Press Association.
The case is due to be heard in court on 17 August.
The NPA accuses the two men and three lower ranking police officers of conspiring to murder Mr Chikane in 1989, when he was secretary-general of the South African Council of Churches.
They allegedly attempted to assassinate the clergyman by placing underwear impregnated with a powerful nerve toxin in his suitcase while he was travelling.
Mr Vlok and Mr van der Merwe were in charge of law and order in South Africa during the late 1980s, a period when emergency laws granted police sweeping powers of arrest and detention against anti-apartheid activists.
The BBC's Peter Greste in Johannesburg says the assassination attempt was one of the most striking cases of the apartheid regime's attempt to silence its opposition.