Auction house Bidders Choice was hoping to raise between R2.5-million and R3-million for the three-storey property, The Star reported on Wednesday.
Bidders Choice spokesperson Pieter Geldenhuys said there were a lot of keen buyers even though the house was only 50% complete.
"At the moment, in excess of 30 people have shown interest," Geldenhuys was quoted as saying. He said he was still registering bidders.
Those wanting to bid on the mansion had to pay a registration fee of R100 000, which was refundable after the auction.
The home was attached by the court to help cover Malema's tax bill. He owes the South Revenue Service R16-million. Malema bought the property in 2009 for R3.6-million.
He had the existing structure torn down and began building his own house with a private cinema room, a cigar lounge, a pool and a spa bath, a wine cellar, a coffee bar and provision for a lift.
There was also a "song room". However, it had no fittings, flooring, plumbing or windows yet.
"What you have here is something that is proper style, high tech and very modern," said Geldenhuys. According to the newspaper, open viewing days had been held the past two Sundays. – Sapa