BlueRock Diamonds, which owns and operates the Kareevlei mine in South Africa, has raised £575,000 in a placing of shares at 0.3p each.
The funds raised would be used to continue to progress the development of Kareevlei, it said.
BlueRock said the recent recovery of large, high quality gem diamonds had encouraged the company to look at ways to fast track its production targets.
It unearthed a 16.28 carat diamond of gem quality last week and an exceptional 8.97 carat diamond at beginning of this month.
“Further investment in the crushing circuit will be necessary to achieve this and discussions with industry partners are taking place to address this,” it said.
BlueRock raised £711,000 in November 2018 to further the development of KV1 and KV2 and also to fund minor improvements to the company's operating plant which took place during the Christmas shut down period.
The main development to KV2 would take place in the second half of the year and there had been 340,000 tonnes of waste stripping taken place in KV1 preparing the pipe for efficient long term mining.