Sri Lankan President Mahinda Rajapakse announced on Sunday that natural gas deposits had been found for the first time during exploratory drilling off the island's coast.
The company prospecting in the area, Cairn India, confirmed it had informed Sri Lankan authorities of a gas discovery during its first attempt to drill into the sea floor off the northwest shoreline.
Rajapakse revealed the find while making an address to council workers in the central region of Kandy, where local elections will be held on Saturday.
"President Mahinda Rajapakse in Kandy announced that Sri Lanka has found a gas field for the first time," the government information department said in a text message.
A presidential spokesman said no further details were available.
However Cairn India, which began exploratory drilling in August, issued a statement later Sunday saying the discovery was made at a depth of 4,300 metres (14,000 feet) below sea level.
"Further drilling will be required to establish the commerciality of the discovery," Cairn India, a unit of British exploration firm Cairn Energy, added.
Cairn India started drilling in the Mannar Basin off Sri Lanka after seismic studies suggested oil and natural gas deposits.
Sri Lanka, which depends on imports for all its petroleum requirements, has also offered blocks to India and China.
Russians carried out the first drilling in the region in 1971 without any commercial success and the government subsequently abandoned the search until Norwegians helped with new seismic studies in the past decade.
London-listed mining group Vedanta Resources, led by Indian-born billionaire Anil Agarwal, is set to take over Cairn India after receiving formal conditional approval from the Indian government.