Shanley, who is based in the UK but is involved in several projects in the Republic, owns an 8.52% stake in Cape Diamonds. The mineral explorer floated on the Alternative Investment Market in May last year, raising £13m and valuing the company at over £82m (�?�124m).

Last week the company's three non-executive directors resigned from the board after a meeting with broker WH Ireland. They are believed to have expressed concern over the management of Cape Diamonds.

Last week it emerged that an unregulated investor relations consultant helped raise more than £12m for Cape Diamonds and was paid £600,000 for doing so. The miner confirmed the three non-executive directors have left the firm but declined to elaborate in a statement to the stock exchange.

Cape Diamonds had planned to restart an idle South African diamond mine, Elandslaagte, from which the company had extracted 2,000 carats since 2004 as part of an evaluation of the site.

In 2004, 78-year-old Shanley got permission for an �?�110m development in Waterford through a company called Fosbern Manufacturing. One its directors is Patrick Tattan, who is also a director of Shanley Holdings, which owns the stake in Cape Diamonds.

Shanley was one of a number of individuals who refused to cooperate with inspectors who compiled the 2002 report into offshore Ansbacher accounts.