The ANC has since jumped on the bandwagon, calling for the "relevant authorities" to "urgently" investigate the allegations.
The governing party said in a statement: "Those found guilty of race-based pricing should face the full might of the law.
"We further insist that clients who have been at the receiving end of this unethical business practice should be reimbursed and have their payments recalibrated to reflect the true cost of the loan.
"If proven to be true, the red-lining by financial institutions perpetuates racial inequalities and effectively prevents black people from owning assets. It also reinforces apartheid spatial patterns by putting constraints on the location decisions of black households."