On Thursday, Zimbabwe's information ministry tweeted that oil had been discovered.

But in a statement to the Australian Stock Exchange, Invictus put a dampener on Zimbabwe's expectations of an oil bonanza saying "an oil or gas discovery has not been made".

It added that there were indications of oil which could only be confirmed by drilling an exploration well.

Zimbabwe's Mines Minister Winston Chitando said the well would be sunk in 2020 at a cost of $20m (£15.35m).

He said that this will be the largest undrilled onshore resource in Africa.

Invictus is using data first gathered by Mobil Oil during its studies in the 1990s.

Reuters reports Mr Chitando as saying that Invictus had made more progress than Mobil because it had a better knowledge of the Muzarabani basin which has a similar geological structure to Uganda and Kenya, where oil has been discovered.