Communications Minister Dina Pule and her boyfriend are accused of using sponsors' funds to buy her luxury gifts, the Sunday Times reported on Saturday.
Pule and Phosane Mngqibisa have also been on no fewer than 19 overseas trips together, the newspaper alleged.
Mngqibisa who allegedly got a subcontract for the Cape Town ICT Indaba through Pule, was accused of looting part of a R36-million sponsorship meant for project.
Mngqibisa, who had signing rights to an account of the Indaba organiser, Carol Bouwer, last week allegedly withdrew R100 000 from the project funds for a trip to Barcelona.
He allegedly purchased a pair of French designer shoes for the minister while on this trip.
"I'm not sure why the shoes were bought but I recall an incident where I was told the wrong invoices were submitted," Bouwer was quoted as saying.
Sunday Times also alleged that Mngqibisa withdrew millions from Bouwer's account to supposedly pay suppliers but the cash has not been accounted for.
It was also reported that Pule managed to get Telkom, MTN and Vodacom — all companies she regulated — to donate millions towards the Indaba.
Pule reportedly declined to speak to the Sunday Times about the matter.
Mngqibisa however, acknowledged that he had been on several business trips and confirmed that Pule had been on some of the trips.
These revelations will add to the pressure that Pule already faces from parliaments ethics committee, which on Wednesday met to discuss the conflict of interest in her boyfriend holding the purse strings for the Indaba, the paper reported.