Islamabad, Pakistan (CNN) -- A kidnapped ex-Pakistani intelligence agent who once worked alongside the CIA and eventually became a staunch Taliban supporter has died, Pakistani officials told CNN.
Col. Sultan Amir Tarar, also known as Col. Imam, died in North Waziristan, one of the districts in Pakistan's tribal region along the border with Afghanistan, said government official Tariq Hayat Khan.
Another Pakistani intelligence official, who asked not to be named because he is not authorized to speak to the media, confirmed Tarar's death although neither could confirm how he died.
Some Pakistani media have reported Tarar was killed by his captors.
Militants kidnapped Tarar last year while he was traveling to Pakistan's tribal region along with another former Pakistani intelligence agent named Khalid Khawaja and a Pakistani filmmaker.
The two former spies were acting as guides for the filmmaker, who was working on a documentary about militants in Pakistan.
The kidnappers demanded the release of three Afghan Taliban leaders in return for the release of the three hostages, an Afghan Taliban source told CNN at the time.
In April of last year Pakistani officials confirmed Khawaja's body was found in a village in North Waziristan, widely believed to be a stronghold of the Pakistani Taliban and other al Qaeda-linked groups fueling the insurgency in Afghanistan. Khawaja was shot three times in the chest, officials said.
Pakistani media reported that a letter found next to Khwaja's remains accused him of being a government spy and was signed by a little-known militant group called the Asian Tigers.
"This is Khalid Khawaja who has been working for ISI and the CIA, the biggest enemy of Muslims," the letter said, referring to Pakistan's Inter-Services Intelligence, the country's top spy agency, and the U.S. Central Intelligence Agency.
In September, Pakistani government officials said the filmmaker had been released but gave no details about Tarar's whereabouts and condition.
Tarar was a retired member of the ISI. Analysts say he played a pivotal role with the CIA in training the Afghan mujahedeen during the 1980s jihad against the Soviet occupation of Afghanistan.
After the Soviets were defeated and the United States pulled out of the region, Tarar became a staunch supporter of the Taliban regime in Kabul and a fierce critic of the U.S. government and the U.S. occupation of Afghanistan after the September 11, 2001, terrorist attacks.
Analysts say Tarar's kidnapping by militants underscores the emergence of a motley collection of rival militant groups in Pakistan's tribal region, each with different objectives and allegiances.
"You will find there are two militant factions in Pakistan," said Muhammad Amir Rana, head of an Islamabad-based think tank that monitors militant activity in the region. "One faction still has links with Pakistan's security establishment and the other is revolting because it calls the security establishment puppets of the U.S. and Pakistan government."
Journalist Nasir Habib contributed to this report.
