An oil exploration firm said Thursday that it had discovered there were 100 billion barrels of oil in the ground next to Gatwick Airport outside London.
Although only between three and 15 percent of the total is likely to be extractable, UK Oil & Gas Investments (UKOG) said the Horse Hill well in Surrey, southwest England, was a "world class potential resource".
"We think we've found a very significant discovery here, probably the largest (onshore in the UK) in the last 30 years, and we think it has national significance," Stephen Sanderson, the firm's chief executive, told the BBC.
UKOG said the controversial technique of fracking should not be necessary to extract oil from the 55-square-mile (88-square-kilometre) site.
Its finding comes despite the British Geological Survey, a government organisation, reporting last year that the region may only have between 2.2 and 8.5 billion barrels of oil.
Some 2,000 oil wells have been drilled in Britain since the 19th century and 250 are still operational, producing between 20,000 and 25,000 barrels of oil equivalent per day.