Exploration minnow African Diamond's first-half pretax losses grew to £176,000 (€259,127) from £120,000, as the company failed to generate any revenue.

Nevertheless Dr John Teeling, chairman of the AIM-listed company, said yesterday that African Diamond's future was bright. The firm was going through a period of "intense activity", he said, with exploration activity focusing on the Orapa area of Botswana, where the company operates a joint venture with De Beers.

Production at African Diamond's first discovery - the AK6 pipe in Orapa - is expected to begin in 2009. The AK8 pipe is now at an advanced exploration stage, while three other discoveries in the Orapa area are being intensively explored.

The company recently acquired a 35.4 per cent stake in Bugeco, a Belgian company which has discovered two new clusters of Kimberlite - a type of rock which sometimes contains diamonds - in Congo.