(Recasts with EFF, adds quote, details)
JOHANNESBURG, June 9 (Reuters) - South Africa's ultra-left Economic Freedom Fighters (EFF) party filed a criminal complaint against Finance Minister Malusi Gigaba and the state rail company on Friday over what it says is evidence of corruption in a lucrative government tender.
A flurry of new allegations of inappropriate collusion between state-owned companies and business interests close to President Jacob Zuma this week have piled pressure on the scandal-plagued leader and emboldened opposition parties.
Some of more than 100,000 emails leaked to media show a company owned by the Gupta family, friends of Zuma, allegedly earned 5.3 billion rand ($410 million) by acting as an intermediary in a tender to build locomotives for state rail firm Transnet.
"We are here because we want to protect the South African purse, which Zuma and his friends have turned into a personal purse," EFF head Julius Malema said after filing the complaint at Johannesburg's central police station.
Gigaba has said he has done nothing wrong.
A Gupta family spokesman has said the emails are "fake news". Zuma has not addressed the new allegations but has previously said his relationship with the Guptas does not represent a conflict of interest.
The African National Congress (ANC) has become increasingly divided over Zuma's leadership in recent months due to a string of corruption scandals, diminishing public support and economic turbulence caused partly by a cabinet reshuffle in March.
Zuma, who has survived calls to resign from sections of the ANC and its political allies in recent months, said on Friday the party must put a stop to public spats and unite to avoid handing the advantage to its opponents.
"We must unite and close ranks and find solutions to the challenges we face," Zuma told veterans of the ANC's military wing. "We cannot afford anymore self-inflicted pain."
$1 = 12.9117 rand Reporting by Nqobile Dludla and Tanisha Heiberg; Writing by Joe Brock; Editing by Ed Stoddard