The CIA is secretly using an airbase in southern Pakistan to launch the Predator drones that observe and attack al-Qaeda and Taleban militants on the Pakistani side of the border with Afghanistan, a Times investigation has found.

The Pakistani and US governments have repeatedly denied that Washington is running military operations, covert or otherwise, on Pakistani territory — a hugely sensitive issue in the predominantly Muslim country.

The Pakistani Government has also repeatedly demanded that the US halt drone attacks on northern tribal areas that it says have caused hundreds of civilian casualties and fuelled anti-American sentiment.

But The Times has discovered that the CIA has been using the Shamsi airfield — originally built by Arab sheikhs for falconry expeditions in the southwestern province of Baluchistan — for at least a year. The strip, which is about 30 miles from the Afghan border, allows US forces to launch a Drone within minutes of receiving actionable intelligence as well as allowing them to attack targets further afield.

It was known that US special forces used Shamsi during the invasion of Afghanistan in 2001, but the Pakistani Government declared publicly in 2006 that the Americans had left it and two other airbases.

Key to the Times investigation is the unexplained delivery of 730,000 gallons of F34 aviation fuel to Shamsi. Details were found on the website of the Pentagon’s fuel procurement agency.

The Defence Energy Support Centre site shows that a civilian company, Nordic Camp Supply (NCS), was contracted to deliver the fuel, worth $3.2 million, from Pakistan Refineries near Karachi.

It also shows the fuel was delivered last year, when the United States escalated drone attacks on Pakistan’s lawless tribal areas, allegedly killing several top Taleban and al-Qaeda targets, but also many civilians.

A source at NCS, which is based in Denmark, confirmed that the company had been awarded the contract and had supplied the fuel to Shamsi, but declined to give further details.

A spokesman for the US embassy in Pakistan told The Times: “Shamsi is not the final destination.” However, he declined to elaborate and denied that the US was using it as a base.

“No. No. No. No. No. We unequivocally and emphatically can tell you that there is no basing of US troops in Pakistan,” he said. “There is no basing of US Air Force, Navy, Marines, Army, none, on the record and emphatically. I want that to be very clear. And that is the answer any way you want to put it. There is no base here, no troops billeted. We do not operate here.”

He said that he could not comment on CIA operations.

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