Warrants of arrest have been issued by the Randburg Magistrate's Court for two more family members of Barry Tannenbaum, alleged mastermind of the R12.5-billion Ponzi scheme in which high-profile South African business leaders invested money.

The Sunday Times reported yesterday that Tannenbaum's wife, Debbie, and brother, Michael, face charges of money laundering and fraud. Michael tannenbaum was unaware of the warrant when contacted by the Sunday Times on Friday and strongly denied any involvement,

Arrest warrants for more "key people" are likely to follow in the investigation, which involves 880 investors, 127000 transactions and 10 countries, The Sunday Times said.

The Tannenbaum scam had investors believing they were financing importation of raw materials for the local manufacture of pharmaceutical products, with promised returns of as much as 200% per year.

Debbie Tannenbaum's involvement allegedly dates back to 2006 when she started signing "crucial documents", the sources said. She has allegedly also served as a director and trustee of the Australia-registered Bartan Group, through which accounts about A$100-million (R739-million) was moved.

It is alleged that Michael Tannenbaum was involved in the scheme in the early years, and that guarantees that he had given to New York-based lawyer Meir Levin, an alleged mega-investor, helped the scheme take off. Michael Tannenbaum told the Sunday Times that these guarantees were done in good faith.

"To be clear, I have played no part in, known about or gained from any fraudulent scheme."

Barry and Debbie Tannenbaum's lawyer, Darryl Ackerman, said he was "totally unaware" of the warrant of arrest that had been issued for Debbie. "I find it quite strange. In my opinion, Debbie never had any involvement in that at all." A warrant of arrest for Barry Tannenbaum was issued in 2009.

The couple remain in Runaway Bay in Australia, a source close to the investigation said.