JOHANNESBURG (Reuters) - South Africa’s new President Cyril Ramaphosa has changed a rule that said evidence produced at a judicial inquiry into allegations of influence-peddling signed by his predecessor Jacob Zuma could not be used in a criminal case.

FILE PHOTO: President Cyril Ramaphosa delivers his State of the Nation address at Parliament in Cape Town, South Africa, February 16, 2018. REUTERS/Ruvan Boshoff/Pool

The modification of a rule made by Zuma is fresh evidence of Ramaphosa’s determination to follow through on a pledge to crack down on graft. Ramaphosa was elected by parliament to succeed Zuma in February in part on his pledge to curb corruption.

Zuma signed the clause on Feb. 8 as part of a list of regulations before he stepped down from office.

The regulations govern an inquiry into allegations that Zuma’s friends, the businessmen and brothers Ajay, Atul and Rajesh Gupta, influenced the appointment of ministers and the award of contracts by state firms.

Zuma and the Guptas have denied any wrongdoing.

Civil rights group AfriForum filed an application at South Africa’s highest court, the Constitutional Court, to quash the rule signed by Zuma, which it termed “unconstitutional”.

The rights group said the clause, as signed by Zuma, would mean that no evidence regarding the questions and answers in the inquiry will be admissible if there are subsequent criminal proceedings. It said this would turn the commission of inquiry into an amnesty tribunal.

In a statement on Friday, the president’s office said Ramaphosa had amended the rule in response to petitions filed by AfriForum and other rights groups.

Zuma lost support within the ruling African National Congress because of the allegations and they remain politically potent even though he has stepped down.

Conducting a credible inquiry is seen by many as a litmus test of Ramaphosa’s ability to pursue broader reforms in his bid to revive the country’s economy.

Ramaphosa re-wrote the clause, limiting the inadmissibility of any evidence to circumstances where a witness may incriminate themselves.

AfriForum said following it would drop its case following Ramaphosa’s amendment of the rule.

“We won’t be proceeding with the case,” AfriForum’s spokesman Willie Spies said.

Zuma, 75, announced in January that he would set up the commission into influence-peddling, which has become known as “state capture” in South Africa, after he was ordered to do so within 30 days of a High Court ruling in December.