n arrest warrant was issued on Tuesday for South Africa's former president Jacob Zuma after he failed to appear at a pre-trial hearing on fraud, corruption and racketeering charges related to a 1990s arms deal.

Zuma's lawyers blamed ill-health for the 77-year-old's absence, and the execution of the warrant was deferred until May 6, when the long-running case is due to resume.

It is far from the first scandal to hit Zuma, who reluctantly stepped down under pressure from his ANC party in February 2018 in the face of mounting allegations that his friends, the wealthy Gupta family, had undue influence on his administration.

Here are five of his biggest scandals:

Arms deal

Corruption charges have long loomed over Zuma in relation to a multi-billion-dollar arms deal signed in 1999 when he was deputy president.

He and other officials are alleged to have accepted bribes from five European arms manufacturers to influence the choice of weaponry bought in the deal.

But the charges were shelved in 2009 -- the year Zuma became president.

After protracted back-and-forth court cases, in March 2018 -- a month after he resigned as president -- national prosecutors decided Zuma was liable to face prosecution on 783 counts of corruption, fraud, racketeering and money laundering charges relating to the arms deal.

Zuma's advisor, Schabir Shaik, was jailed for 15 years in 2005. He was released on medical parole in 2009 after Zuma became president.

The former president faces jail for the criminal charges over hundreds of payments he allegedly received, valuing a total of $270,000.

Zuma denies the charges.

Nkandla residence upgrades

South Africa's graft watchdog in 2014 found Zuma to have "benefited unduly" from so-called security upgrades to his rural Nkandla residence in KwaZulu-Natal province.

The work, paid for with taxpayers' money, cost $24 million and included a swimming pool -- which was described as a fire-fighting facility -- as well as a cattle enclosure, an amphitheatre and a visitors' centre.

For two years, Zuma fought the order to repay part of the money. The scandal came to dominate his presidency, with opposition lawmakers chanting "Pay back the money!" every time he appeared in parliament.

In March 2016 the constitutional court ordered Zuma to pay back the cash, the judges accusing him of failing to respect and uphold the constitution.

Guptagate

As the Nkandla debacle built to a climax, its place in the headlines was overtaken by a new scandal, known as Guptagate.

The scandal involved the president's allegedly corrupt relationship with a wealthy family of Indian immigrants headed by three brothers -- Ajay, Atul and Rajesh Gupta -- who built a business empire in mining, media, technology and engineering.

Smouldering rumours of the family's undue influence on the president burst into the open in 2016 when evidence emerged that the Guptas had offered key government jobs to those who could help their business interests.

Former deputy finance minister Mcebisi Jonas revealed that the Guptas had offered him a promotion shortly before Zuma sacked respected finance minister Nhlanhla Nene in December 2015.

Rape charges and HIV myth

Before taking office, Zuma was put on trial in 2006 for rape, in a case that dismayed many South Africans.

Zuma said the sex with the 31-year-old family friend was consensual and he was acquitted.

But he told the court he had showered to avoid contracting HIV after having unprotected sex with his HIV-positive accuser -- a common but dangerous myth.

Zuma was head of the South African National AIDS Council at the time, and was pilloried for his ignorance.

Nearly a fifth of South Africans aged between 15 and 49 are HIV-positive.

Omar al-Bashir

Then Sudanese president Omar al-Bashir was allowed to attend a meeting of the African Union in Johannesburg in 2015, despite an arrest warrant from the International Criminal Court on charges of war crimes in the conflict in Darfur.

The government said the fact that he was attending the summit as a head of state meant he had immunity, but the court disagreed.

Zuma faced an impeachment vote in parliament over the issue in September 2016, but ANC lawmakers voted overwhelmingly against it.