The Reserve Bank had discovered evidence of the theft of “R5 circulation coins” and had referred its findings to the Hawks, Hlengani Mathebula, the head of strategy and communications at the central bank, said on Friday.

“The crime was ostensibly committed by a number of employees who appeared to have acted in collusion with what appears to be a syndicate-style operation that included external parties. Appropriate steps have been taken and all evidence gathered has been handed over to the police’s Directorate of Priority Crime Investigation (the Hawks).”

Asked for additional details yesterday, he refused to comment further, given that the Hawks were now conducting their own enquiries.

Mathebula said the investigation into the theft had been carried out alongside an enquiry relating to gold coins produced by a subsidiary of the central bank that “failed to meet required quality specifications”. That discovery led to the suspension of two officials in December last year. He said investigations had revealed some of the proof Krugerrand coins cast between April and May last year “may not meet all the required quality specifications”.

In December last year, the bank announced the suspension of Andile Mvinjelwa, the managing director of the SA Mint Company, and Tom Davel, the general manager of the numismatic coins division, “pending investigations”.

A statement from the bank yesterday stressed the distinction between bullion Krugerrand coins and proof Krugerrand coins. It said proof coins were targeted at the collectors’ market and were produced in much smaller quantities than the bullion coins.

“During the period April 1, 2010, to October 31, 2011, a number of gold blanks of different sizes were manufactured by the SA Mint. As a further precautionary measure it was deemed important that an intensive assessment of all Krugerrand proof coins that were still in the stock of our dealer network be undertaken.”

The verification process revealed that “some coins appeared to be under specification to varying degrees”.

“The SA Mint and the bank contacted relevant local and international dealers and also held meetings with dealers to inform them of this possibility. An offer was made that, should any of the dealers have reasonable concerns that some proof Krugerrand coins may not comply with all required quality criteria, they could return such coins to the SA Mint.”

These investigations followed problems at another Reserve Bank subsidiary the previous year.

In November 2010, the bank announced the suspension of Musa Mbhele, the managing director of the SA Bank Note Company, because it had become aware of certain “issues” within the company’s technical operations. It said Mbhele’s suspension followed the signing of contracts with the central banks of Namibia and Zambia that the company did not have the capacity to fulfil.

But, at the time, the suspension was seen to be linked to the circulation of defective R100 banknotes that were later replaced.