The development of Mozambique's gas resources could generate about $21.4bn for its economy over the next 25 years, a report suggests.

PLJ Financial Services believes that it could also change the South African economy, reducing its reliance on oil and providing an alternative to cheap coal.

Dawie Roodt, chief economist at PLJ Financial Services, estimates that Mozambique could earn about $400m a year from the gas produced.

Considering that "the Mozambique economy for a whole year is roughly about $4bn...then obviously this is really something...a very large project for the whole economy," he told the BBC's World Business Report.

This could add 10% to national economic growth for the next two years, and 2% every year after that.

It will also benefit its end-user, South Africa, to the tune of about $3.2bn over 25 years.

The biggest consumer of Mozambique's gas is likely to be South Africa's Sasol, who is expected to use the gas in its chemical production as well as to produce petrol.