Former South African president Jacob Zuma has abandoned his testimony to a state commission investigating corruption allegations after claiming he is being treated unfairly.

The commission is probing wide-ranging allegations of corruption in government and state-owned companies. His lawyers said on Friday that Mr Zuma, who denies the allegations, will no longer participate.

Mr Zuma was president from 2009 to 2018, when he resigned under pressure from his ruling African National Congress party and was replaced by Cyril Ramaphosa.

South Africa Zuma
Former South African president Jacob Zuma has been accused of corruption (Mike Hutchings/AP)

He began his testimony this week by calling the allegations part of an international intelligence conspiracy that began more than 25 years ago to assassinate his character.

He has been questioned about his close relationship with the wealthy Gupta family and allegations that they exerted influence over cabinet appointments and state contracts.

Deputy chief justice Raymond Zondo later said an agreement had been reached that will allow Mr Zuma to return at a later stage. If the parties cannot agree on when, Mr Zondo said that he would decide.

Mr Zuma will be provided with an outline of the specific issues on which he will be questioned.