The Democratic Alliance on Sunday said that it had formally applied to see the business contract apparently signed by Andile Ramaphosa, the president's son, and corruption-accused company Bosasa.
"I have today submitted two separate applications in terms of the Promotion of Access to Information Act (PAIA) - one to the Presidency and one to the African Global Group, formerly Bosasa - to gain access to the contract for services rendered by the President's son," DA leader Mmusi Maimane said in a statement.
"Earlier this week in Parliament, I asked President Ramaphosa whether he had any knowledge of an alleged R500 000 payment to Ramaphosa Jr from Bosasa CEO, Gavin Watson. I presented both a proof of payment and sworn affidavit supporting this payment.
"President Ramaphosa responded by confirming the payment, but then said his son had explained it as a payment received for legitimate 'consulting' services. He further said that there is a contract between his son and Bosasa for these services, and he had personally seen this contract."
In Parliament, Ramaphosa told Maimane that he had questioned Andile himself and was satisfied that there had been no irregularity or corruption in his business dealings.
He confirmed that his son had a legitimate business contract with Bosasa through his company, which offers financial consulting services.
However, speaking shortly after his father's declaration, Andile Ramaphosa denied that the R500 000 payment by Bosasa was for his benefit. Ramaphosa Jr was adament that the particular payment which the DA had flagged had "nothing to do with him".
"I have absolutely nothing to do with this. I have never received such a payment," he told News24 at the time.
On Sunday, Maimane said he had made the applications to gain access to the contract to ensure that Andile Ramaphosa "has not received any preferential treatment - including alleged kickbacks - by virtue of him being the son of President Cyril Ramaphosa".
Maimane alleged that Andile Ramaphosa was "directly involved in no less than 30 companies". He said any of these may have been rendering services to Bosasa.
He said that despite President Ramaphosa speaking "tough" in Parliament, he had not released the contract as the DA had asked at the time.
Maimane said he had also asked the president to explain the exact nature of the services his son rendered to Bosasa as well as why the R500 000 payment was made to a trust, and not a business account.
"Any shadow of doubt pertaining to the President's immediate family must be thoroughly interrogated to ensure that no undue influence, malfeasance or corruption is present."
Furthermore, suggested Maimane: "If there is nothing to hide, both Andile Ramaphosa and African Global Group (Bosasa) should have no hesitation in releasing the contract that underpins their agreement and relationship."