Two judges have been replaced on the board of inquiry into allegations of misconduct by National Police Commissioner Bheki Cele and on the commission of inquiry into the arms deal, the presidency said on Friday.

Retired Constitutional Court Judge Yvonne Mokgoro, who was going to chair the inquiry into the allegations of misconduct in relation to the procurement of office accommodation in Pretoria and Durban for the South African Police Service, had been replaced by Judge Jake Moloi, President Jacob Zuma's spokesperson Mac Maharaj said in a statement.

Justice department spokesman Tlali Tlali was not immediately available to explain why she had been replaced.

There are also two additional members on the board of inquiry --advocates Terry Motau SC and Anthea Platt.

Deputy Judge President of the High Court in Pretoria, Justice Willem van der Merwe, who was set to sit on the commission of inquiry into the arms deal, had asked Zuma to release him from the arms probe, said Maharaj.

"He asked to be released... for personal reasons," he said.

On Monday, Zuma announced the judges appointed to the arms deal commission of inquiry and the board of inquiry into the lease agreements.

Supreme Court of Appeal Judge Willie Seriti would chair the commission of inquiry into the arms deal.