The Irish company, which is also searching for diamonds in parts of western Africa, has a 49% stake in the Botswana venture, with the remainder being held by De Beers. Once a feasibility study has been completed and drilling commences, African Diamonds stake will fall to 30%.

A definitive diamond valuation exercise is due to take place in May. African Diamonds said in January the diamond discovery in Botswana could be worth as much as $360 million. John Teeling, the companys chairman and founder, said the discovery would be "the making of our company." The exploration company, whose shares are listed on Londons Alternative Investment Market, raised GBP4.5 million ($6.4 million) from a private placement in January and has enough working capital to fund its Botswana project beyond the end of this year.

African Diamonds Exploration group said production from its Botswana diamond joint venture with De Beers could begin as early as 2008 and has the potential to become one of the worlds top diamond mines. The Dublin-based company said the conceptual study report for its AK6 diamond discovery at the Boteti Exploration project is expected to be completed by the end of 2006, some 12 months ahead of schedule.