Botswana Diamonds said it had identified what it believed to be kimberlite pipes, buried at shallow depth, at its Thorny River project in South Africa.
The targets, identified by geophysical work, were very similar to the pipe that constituted the high-grade and De Beers Marsfontein mine.
They were similar in so much as the pipe had little surface indication due to dolerite rock cover, but grew and swelled below the dolerite, Botswana Diamonds said.
Chairman John Teeling said it had long been held that there should be high-grade kimberlite pipes other than the Marsfontein mine in the Thorny River area, but the geology made discovery difficult.
'New geophysical technology tries to see through the dense dolerite cover,' Teelign said.
'The company pioneering the work, Subterrane, believe they have identified five targets likely to be kimberlites.'
Teeling said the company was working to better define where to drill.
'The targets are shallow so will not be expensive to drill,' he said.
At 2:02pm: (LON:BOD) Botswana Diamonds PLC share price was +0.04p at 0.58p