UPDATE 5-Defiant at inquiry, South Africa's Zuma denies breaking law with business brothers

* Zuma denies breaking law with Gupta family

* He says he is victim of plot that began decades ago

* 'Hands off Zuma', say supporters

* ANC 'not on trial' says party spokesman (Updates with more Zuma comments, remarks by opposition lawmaker, ANC spokesman, Zuma supporter)

By Alexander Winning

JOHANNESBURG, July 15 (Reuters) - Former South African President Jacob Zuma told a corruption inquiry on Monday that enemies had plotted to bring him down, and he had never broken the law with the business family at the centre of an influence-peddling scandal.

Zuma struck a defiant tone at the public inquiry, saying he was the victim of a "character assassination" by enemies who had tried to get rid of him for more than 20 years.

His appearance at the inquiry – set up to test allegations that Zuma allowed cronies to plunder state resources and influence government appointments – marked a dramatic fall from grace for a politician who long dominated the country's politics.

Zuma, ousted by the governing African National Congress (ANC) in February 2018 and replaced by President Cyril Ramaphosa, has consistently denied wrongdoing over his nine years in power.

Referring to the three Gupta business brothers, Zuma said: "I never did anything with them unlawfully, they just remained friends. Never, never did I discuss any matter that does not belong to them".

"They were businesspeople and successful businesspeople," Zuma continued. "I'm not a businessperson, I know nothing about business, I'm a politician, I know something about politics."

Under pressure from rivals in the ANC, Zuma set up the corruption inquiry he now sits before in his final weeks as president, as a number of his colleagues, including Ramaphosa, feared scandals surrounding Zuma could indelibly tarnish the party's reputation.

Zuma had avoided establishing the inquiry since a 2016 report by South Africa's anti-corruption watchdog, the public protector, instructed him to do so to investigate allegations that three Gupta brothers had been able to influence ministerial appointments and had won state contracts improperly.

The Gupta family denied the accusations and left South Africa around the time that Zuma was ousted.

'VILIFIED'

"I've been vilified, alleged to be the king of corrupt people," Zuma, 77, said in his opening remarks to the hearing in Johannesburg, which was being broadcast live on South African television. "There has been a drive to remove me from the scene...a conspiracy against me."