The CIA has pulled its station chief from Islamabad, one of America's most important spy posts, after his cover was blown in a legal action brought by victims of US drone strikes in the tribal belt.

The officer, named in Pakistan as Jonathan Banks, left the country yesterday, after a tribesman publicly accused him of being responsible for the death of his brother and son in a CIA drone strike in December 2009. Karim Khan, a journalist from North Waziristan, called for Banks to be charged with murder and executed.

In a rare move, the CIA called Banks home yesterday, citing "security concerns" and saying he had received death threats, Washington officials told Associated Press. Khan's lawyer said he was fleeing the possibility of prosecution.

"This is just diplomatic language they are using. Banks is a liability to the CIA because he's likely to be called to court. They want to save him, and themselves, the embarrassment," said lawyer Shahzad Akbar. Pakistani media reports have claimed that Banks entered the country on a business visa, and therefore does not enjoy diplomatic immunity from prosecution.

The recall comes at a sensitive moment for Washington. This week's Afghanistan policy review brought fresh focus on Taliban safe havens in Pakistan's tribal belt. Meanwhile CIA drone attacks – which are co-ordinated from the Islamabad embassy – have reached a new peak. Three drones struck targets in Khyber, a previously untouched tribal agency, on Friday, reportedly killing 24 people and signalling a widening of the CIA covert campaign.

The drones enjoy quiet support from the Pakistani government and military but are intensely unpopular among the wider public. Public anger over civilian casualties has focused on Karim Khan, who first publicised his case with a $500m (£323m) civil law suit that named Banks, CIA director Leon Panetta and the US defence secretary, Robert Gates, as respondents.

Few legal experts expect the case to succeed, but it has renewed uneasiness over drones. There have been over 100 strikes so this year, twice as many as in 2009.

The identity of the CIA station chief is a closely guarded secret in any country. Khan's lawyer said he had obtained Banks's name from one Pakistani journalist and confirmed it with a second. "I asked around, then got an answer after three or four days of searching," he said.

There was also speculation that Banks could have been named by a disgruntled element within Pakistan's Inter-Services Intelligence spy agency. Last month, several senior ISI officials were named in a New York legal action brought by relatives of the 2008 Mumbai attacks.

It is unusual for the CIA to recall such a senior spy. Station chiefs were recalled from Israel in 1999 and Argentina in 2001 after being identified in the local media. Today, several US media outlets did not name Banks, citing national security concerns. His identity has been widely reported in Pakistan and India.

Akbar, the lawyer, said the unusual legal action had attracted another 14 families of alleged drone victims from the tribal belt. They intend to bring a class action suit against the CIA in early January, he said.