The UK-based company, run by ex-Rio Tinto executive Alan Davies, is developing its flagship Mimbula project in Zambia's copper belt.

The African nation's heavy reliance on diamonds, which account for a fifth of the Botswana's GDP and more than two thirds of its foreign exchange income.

The country was under a strict lockdown to curb the spread of the coronavirus in April last year, denting output.

The southern African nation, the world’s second-biggest diamond producer, has more than 200 billion tonnes of untapped coal reserves.

The government is aiming to end unsafe working practices and child labour.

Tongon went from almost being sold to becoming one of Barrick Gold’s most valued assets.