Shell is one of several firms seeking to explore the semi-desert Karoo region, believed to have one of the largest untapped deposits of its kind in the world.

“We started this process in 2008,” said Bonang Mohale, chairman of Shell South Africa.

“We are now six years down the line and we still don’t have an exploration right agreement in our hands, that’s the first concern,” he said.

An 18-month moratorium on hydraulic fracturing to weigh the environmental and economic implications of the process was lifted in September 2012.

A junior minister recently said exploratory drilling might not get underway until mid-2016 at the earliest.

Mohale said the company “supported” the moratorium to allow the public and the government to educate themselves about the environmental impact of the process known fracking.

But, “we didn’t anticipate that it will take this long,” he added.

Environmentalists have vociferously opposed the drilling for shale gas in the Karoo, saying it has the potential to poison the stark area’s underground water supply.

Fracking involves digging wells up to four kilometres deep, before pumping in a cocktail of water and chemicals to crack the shale rock and release the gas.

Shell plans to spend $200-million for the first exploration phase of six wells if granted a licence to drill.

The Northern Cape Karoo region, near Namibia, has been tipped as potentially one of the world’s largest untapped shale fields.