The party was considering dismissing and criminally prosecuting members found to have raised money outside the ANC's defined formal structures and processes to influence the outcome of conferences.
"Money is a big problem for us in the ANC," he told a media interaction session in Sandton, Johannesburg, on Tuesday.
Mbalula said the party's leaders should be elected on the basis of their ability to lead and not on how well resourced they were.
National executive committee member Febe Gqubule-Potgieter said the use of money in elective processes had been a concern for the ANC "for a while".
She said the party was developing guidelines for lobbying, and those who raised money outside these guidelines could face being disqualified from elections.
Mbalula said money exchanged was like a "ghost". No one knew where the funds came from and the donors often had ulterior motives.
"We provide good food, they eat Nandos... we provide Oros, they drink Fanta," he said of elective conferences.
Gqubule-Potgieter said it was difficult to catch those who obtained money outside the formal processes, and the party might have to rely on whistleblowers to expose the practice.
The ANC's rules for lobbying would be debated at the national general council in September.
Gqubule-Potgieter said it was a time for the ANC to reflect on itself.
"... One of its [the ANC's] strengths has been its ability for self-reflection and its ability to be critical about itself," she said.
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