Known for representing celebrities and high-profile clients, he said he had decided to sell the house. He bought it 18 years ago for R1-million .

The auction will be handled by scandal-hit Auction Alliance.

But Gundelfinger was quick to point out he struck the deal with the company before the claims over rigged auctions and dodgy dealings hit the headlines.

The mansion, in northern Johannesburg, has five reception rooms and "secluded, indigenous, park-like gardens".

It also features five bedrooms with spa-style bathrooms, a pyjama lounge and a gourmet kitchen with separate scullery and laundry.

Outside, it has an entertainment gazebo with change-rooms, shower and cloakroom overlooking a swimming pool and sunken tennis court, four garages and a separate spacious cottage.

Average prices in Sandhurst, arguably the country's priciest suburb, range from R10-million to about R65-million.

Gundelfinger's property, in Coronation Road, is a stone's throw from the mansion bought two years ago by billionaire businessman and Minister of Human Settlements Tokyo Sexwale for a reported R56-million.

Gundelfinger said he would move into a "more manageable-size " property in the same suburb.

Gundelfinger, who once described his best purchase as a Bentley Continental GT Turbo, said his home had become too large for him and his wife.

"We've decided to downscale because our three children have all left home," he said, adding that he decided to sell the property two months ago.

One of his daughters, Lisa, is an advocate who qualified in 2009 and spent a year with her father's law firm, while his other daughter, Justine, is a New York-based model and actress.

He said the auction would be held later this month.

Selling properties - with a reserve price attached - by auction has become a popular trend in Australia, the UK and the US.

Gundelfinger said his reserve price was "private", adding that he had approached Auction Alliance in January and signed a binding contract.

"[It] was prior to the debacle and the disclosures in the media of the alleged irregularities."

The auction house, with offices nationwide, was rocked by controversy last month following allegations of a money-making racket, which prompted CEO and founder Rael Levitt to step down pending an independent investigation.

Gundelfinger has represented, among others, empowerment billionaire Cyril Ramaphosa, former world champion boxer Baby Jake Matlala and Altron Group chairman Bill Venter.

Other clients have included kwaito star Tokollo Tshabalala, former Miss SA Peggy-Sue Khumalo, Rhema Ministries' Pastor Ray McCauley, former SA Airways boss Khaya Ngqula and Liberty International chairman Sir Donald Gordon.