The ANC has warned voters about illegal money-lenders withholding their identity documents, the party said on Monday.

ANC spokesperson Jesse Duarte said in a statement the party had noted the continued illegal business conduct by some micro-lenders of retaining the identity documents of their clients and called for an immediate end to this behaviour."

"These are loan sharks," said ANC spokesperson Brian Sokutu.

"They are basically unscrupulous and illegal and take advantage of pensioners and other vulnerable people."

Loan sharks, people who lend money at often usurious interest rates, sometimes take the ATM cards or identity documents of their victims as collateral.

"The ANC urges all people who are affected to go and collect their identity documents and if they encounter resistance, they should press charges with the police," said Duarte.

"Withholding the identity documents will not only be illegal but will be denying our people their right to determine the government of their choice," she said.

Sokutu could not say exactly where the reports were coming from but said "It's something that's been doing the rounds for some time in the country."

Gauteng SA Police Service director Govindy Mariemuthoo said he had not yet heard of any reports of loan sharks keeping identity documents.

"What I know of from previously is that people [loan sharks] take ATM cards and pin numbers," said Mariemuthoo.