JOHANNESBURG, South Africa — In a severe legal blow to Jacob Zuma, South Africa’s former president, national prosecutors announced on Friday that they would reinstate corruption charges against him in a case related to a multibillion-dollar arms deal in the late 1990s.

Shaun Abrahams, South Africa’s chief prosecutor, said there were “reasonable prospects of a successful prosecution” of Mr. Zuma.

The announcement was the latest — though not, most likely, final — chapter in a long-running corruption case that nearly derailed Mr. Zuma’s bid for the presidency, tarnished the image of South Africa’s governing African National Congress and laid the seeds of a culture of graft that has flourished in recent years.

Mr. Zuma, who was ousted last month as president by the A.N.C., was the leader of the party and the nation’s deputy president when the arms deal was finalized in 1999.

Over the past decade, Mr. Zuma has used legal maneuvers and the power of the presidency to avoid prosecution. He was originally indicted in 2007 on 18 charges of corruption, fraud and racketeering, including accepting bribes from a military contractor. At the time, Mr. Zuma, who has always maintained his innocence, was forced to resign as deputy president by President Thabo Mbeki. The case became entwined in a power struggle between the two men.

Mr. Zuma’s supporters have long argued that the case was politically motivated and that he was singled out while other A.N.C. officials implicated in the deal were never charged.

He successfully resurrected his bid for the presidency after the chief prosecutor dropped the charges against him in 2009, accusing his own officials of political interference.

The main opposition party, the Democratic Alliance, challenged the chief prosecutor’s decision, but Mr. Zuma successfully avoided prosecution during his presidency. In 2016, South Africa’s High Court judged that the chief prosecutor’s decision to set aside the charges was “irrational” — a ruling that was upheld by the Supreme Court last year. Legal experts said that it would have been difficult for Mr. Abrahams, who was considered close to Mr. Zuma, to not reinstate the charges against the former president.

Pierre de Vos, a constitutional scholar at the University of Cape Town, said that the corruption case against Mr. Zuma could yet drag on for years. Mr. Zuma could still mount legal challenges to the chief prosecutor’s decision, including eventually going to the Constitutional Court.

“It’s been the former president’s strategy to use every legal loophole to actually avoid having his case being heard in court,” Mr. de Vos said. “If he has the money for lawyers, he could stay out of court forever.”