Police in Pakistan say the lead prosecutor in the murder case of former prime minister Benazir Bhutto has been shot dead in Islamabad.

Police say Chaudry Zulfikar was shot multiple times Friday as he was driving to court.

Zulfikar was investigating the December 2007 assassination of Ms. Bhutto. No one has been convicted or jailed for her death.

Former president Pervez Musharraf, who recently returned to Pakistan after nearly four years of self-imposed exile, is accused in the case. On Tuesday, a court in the northwestern city of Peshawar banned Mr. Musharraf from seeking public office, despite his stated plans to run for a parliamentary seat in May 11 elections.

Since his return, the former president's fortunes have gone from bad to worse. A court on April 20 placed Mr. Musharraf under house arrest in connection with charges that he ordered the illegal detention of judges in 2007. Days later, a judge rejected bail for Mr. Musharraf.

A U.N. report in 2010 said any credible investigation of Ms. Bhutto's death should not rule out the possibility that members of Pakistan's military and security establishment were involved.

Anti-terrorism authorities are probing claims that the then-president failed to provide adequate security to Ms. Bhutto, his political rival, who was gunned down at a political rally in the garrison city of Rawalpindi.

Mr. Musharraf has denied any involvement and he says the allegations against him are politically motivated.

Mr. Musharraf seized power in a 1999 military coup and ruled for nearly a decade before he stepped down in 2008 and later fled into exile.