Zimbabwe's top diamond producer, Mbada Diamonds, said Tuesday it plans to venture into deep shaft mining to secure its future.

The company said it "intends to invest heavily into mining conglomerate and deep-seated kimberlitic material which is projected to bring more revenue compared to alluvial mining which is on the decline."

The company also said in a statement it had generated $1.036 billion (745 million euros) in sales in the four years it has been mining.

Mbada employs 1,700 workers and is the largest of six diamond miners operating in Zimbabwe's eastern Marange district.

Zimbabwe's government had hoped revenue from the Marange mines together with earnings from tobacco and gold exports would boost the country's economy, which has been on a downturn for over a decade.

But little in remittances has reached the national coffers, with reports of the gems being spirited out of the country by a network of locals and foreign dealers.