Abdul Latif Hakimi has been the Taliban's purported spokesman since early 2004 and frequently speaks with news organisations to take responsibility for attacks.
"Abdul Latif Hakimi has been arrested in Pakistan. The details will be given later," Interior Minister Aftab Sherpao said on Tuesday.
"He was the chief spokesman for the Taliban. He was a Taliban leader. It is an important arrest. It is a big success for law-enforcement agencies."
Hakimi began calling international media from different locations about a year and a half ago, often giving exaggerated or untrue information but offering a balance to US military and Afghan government announcements.
Mobile phone use
The spokesman usually called from satellite phones in a bid to conceal his location. Sometimes he called from Afghan mobile phones and even more rarely he used phones with Pakistani numbers.
He is said to be an Afghan with a southern accent who mainly speaks in Pashto, the language of the ethnic Pashtun community from which the Taliban draw their ranks.
"If he has been arrested, I think it is a good step, a good move. He is against the Afghanistan government"
Senior Afghan official
Hakimi last spoke to reporters on Saturday when he claimed the rebels had carried out an attack in the southern Afghan province of Helmand. Officials said a farmer and a policeman died. Hakimi said three police were killed.
He also claimed responsibility for a bombing at an Afghan army training centre in Kabul on 28 September, in which eight soldiers and a civilian died.
Afghan officials were not aware of the arrest but said it would be a welcome development.
"If he has been arrested, I think it is a good step, a good move. He is against the Afghanistan government," a senior official said.
Pakistan has arrested a string of men with alleged links to the Taliban and to Osama bin Ladin's al-Qaida network since the Taliban was toppled by US-led forces in late 2001. The Taliban has waged an insurgency for the past four years.
This year has been the worst since 2001, with more than 1300 people dying so far, including a number of insurgents.