Anti-fracking protesters fear drilling for shale gas could still take place at a site where conventional oil has been found.

Despite confirmation from the licence holder and operator at the site in Horse Hill, near Horley, Surrey, that it is a "conventional drilling project" with "no unconventional shale targets", members of Frack Free Surrey have voiced concerns that American oil company Magellan, which has a stake in the drilling site, could frack the land.

Magellan's chief executive has also said that the "efforts" being made by Horse Hill Developments will "complement" its own pursuit of the "attractive unconventional development opportunities in the Weald".

Protesters have set up a small camp in woodland close to the site, which is off the A217, and a public meeting hosted by Frack Free Surrey on Monday was attended by about 90 people who are concerned that the drilling at Horse Hill could lead to fracking elsewhere in the South East.

Rob Basto, from Frack Free Surrey, said: "They might be drilling for conventional oil but we believe Magellan is looking for shale gas, and although they are not fracking there, they are checking it out and it's quite likely they could come back and frack in the future."

Mr Basto said he had invited representatives from Magellan and Horse Hill Developments to attend Monday's meeting but did not receive a response.

The Horse Hill-1 exploration well, which is located on the northern side of Weald Basin near Gatwick Airport, will be drilled to a total depth of 8,680ft to test a number of conventional oil and gas targets, a company spokesman said.

He said: "The licence holder and operator, Horse Hill Developments Limited, confirms that this is a conventional drilling project and none of the other partners have any interest in exploring unconventional opportunities.

"There are no unconventional shale targets."

David Lenigas, chairman of Horse Hill Developments, has also confirmed there will be no fracking at the Horse Hill site.

He told BBC Surrey that geologists had suggested that the oil and gas reserves at Horse Hill could be worth about £2 billion, with production beginning in about two years.

Horse Hill Developments has a 60-day permit to carry out the drilling and is expected to be at the site for another four to six weeks, a company spokesman said.

Chief executive Scott Bradley added: "We are delighted with the progress being made and the drilling performance to date.

"We now look forward to the next phase of this conventional project and await our target evaluation results eagerly."

Magellan, which has a 35% interest in the well, has also reiterated that it "will not be hydraulically fractured".

J Thomas Wilson, president and chief executive officer, said: "The Weald Basin has yielded conventional oil and gas production for decades, and I expect Horse Hill Developments will be a strong partner to Magellan in unlocking value from the conventional prospects at Horse Hill and elsewhere in the Weald.

"Their efforts will complement nicely our own pursuit of the attractive unconventional development opportunities in the Weald."

Last summer, thousands of protesters flocked to Balcombe in West Sussex when energy firm Cuadrilla set up a drilling site outside the village.

The company's attempts to drill for oil were disrupted over fears it would lead to fracking and a large number of people, including Green MP Caroline Lucas, were arrested as bids were made to block lorries accessing the site.

Ms Lucas was later cleared of any wrong-doing following a trial at Brighton Magistrates' Court.

Last month, an application by a shale company Celtique Energie to explore for oil and gas in the South Downs National Park was rejected by planners.

The controversial plan for a vertical well near Fernhurst, West Sussex, attracted more than 5,500 objections but members of the South Downs National Park Authority (SDNPA) heeded their officers' recommendations and turned down the application overwhelmingly.