Armed men kidnapped Hayatullah Khan on Monday as he was driving near Mir Ali town, in the North Waziristan tribal region bordering Afghanistan, his brother, Mohammad Ehsan, said.
Maqsood Hassan, the government administrator of the area, confirmed the kidnapping and said authorities were investigating.
There was no indication of why Khan had been kidnapped or whether his abduction was connected with his work as a reporter covering security issues in the region for various publications including the Nation, an English-language daily newspaper.
Khan had been reporting on a blast at a house in nearby Haisori village last Thursday, which Pakistani authorities said killed Abu Hamza Rabia, a high-ranking al-Qaida commander.
Villagers in the area said the blast was caused by missiles fired from an aircraft, possibly a drone, but Pakistani authorities said bomb-making material being stored at the hideout went off, killing Rabia and four others.
Haji Mohammad Siddiq, the owner of the house where the blast happened, is an uncle of the kidnapped journalist.
Siddiq denied that there were any al-Qaida fighters in the house when, he said, it was hit by missiles.
On Sunday, tribesmen in Haisori showed US-marked fragments of missiles they said had hit the house. Khan had taken photographs of the fragments for a photo agency.
Authorities said Rabia's comrades took away his body, which has not been found, but they knew of his death through intelligence reports and message intercepts.
Pervez Musharraf, Pakistan's president, said during a visit to Kuwait on Sunday that Rabia's death was "500 per cent confirmed".