Balochistan police interrogated Musharraf for nearly 4 hours at his farmhouse near Islamabad, and then told reporters he had been arrested in the death Bugti,the Times of India reported.
Musharraf, 69, was head of the Pakistani army when Bugti was killed in a shelling of a mountain hideout during a raid by Pakistani government forces. He was named in 2011 in a warrant issued by a court in Balochistan.
Musharraf -- who returned to Pakistan in March after a self-imposed four-year exile -- has been under house arrest stemming from his conviction for illegally jailing several judges in 2007 and later suspending the nation's constitution because of security concerns.
He returned with the intention of forging a political comeback but a regional court Tuesday ordered him banned for life from holding elective office.
Musharraf's lawyer said he plans an appeal to the Pakistani Supreme Court.