Pakistan's former military ruler Pervez Musharraf was on Thursday formally arrested over the murder of former prime minister Benazir Bhutto, prosecutors said.
The Bhutto case is the second of three cases dating back to his 1999-2008 rule for which Musharraf has been arrested. The latest arrest came a day after a Pakistani court refused to extend his bail.
Musharraf will remain in his villa on the edge of Islamabad where he is already under a two-week house arrest over his decision to sack judges when he imposed emergency rule in November 2007.
"Today FIA (federal investigative agency) formally arrested General Musharraf in the Benazir Bhutto case," prosecution lawyer Chaudhry Azhar told AFP by telephone.
On Wednesday a court in Rawalpindi, the garrison city twinned to Islamabad where Bhutto was killed, rejected Musharraf's bail application.
Musharraf is accused of conspiracy to murder Bhutto, who died in a gun and suicide attack in December 2007.
His arrest and disqualification from contesting elections on May 11 have been a humiliating blow for the former ruler of nuclear-armed Pakistan, who returned home last month promising to "save" the country.
Nobody has been convicted or jailed for Bhutto's assassination on December 27, 2007, despite a long-running court case.
Musharraf's government blamed Bhutto's killing on Pakistani Taliban chief Baitullah Mehsud, who denied any involvement and who was killed in a US drone attack in August 2009.
In 2010 a UN report said Bhutto's death could have been prevented and accused Musharraf's government of failing to give her adequate protection.
Bhutto's son, Bilawal Bhutto Zardari, who is chairman of the outgoing Pakistan People's Party, has accused Musharraf of her murder.