Suspicion has grown over whether the Pakistani policeman who assassinated Punjab Governor Salmaan Taseer acted on his own or was assisted in the act following emergence of a raft of evidence that he had been declared unfit for guarding VIPs because of his extremist leanings.
Several police officials have confirmed that Malik Mumtaz Hussain Qadri, the Elite Force personnel who gunned down Taseer on Tuesday, was removed from Rawalpindi Police's Special Branch about 18 months ago after then regional police chief Nasir Khan Durrani described him as a "security threat".
Despite a recommendation that Qadri, 26, should not be assigned to guard VIPS because of his extremist views, he was deputed to Taseer's security detail on five previous occasions.
Investigators probing the assassination have sought a report from Rawalpindi Police to fix responsibility in this regard.
An investigation team is interrogating eight other personnel of the Elite Force who did not take any action when Qadri shot the Governor at very close range.
Taseer was hit by at least 26 bullets and some reports said Qadri changed the magazine of his assault rifle and continued firing.
Investigators were of the opinion that the failure of the other guards to stop Qadri as he fired three bursts had strengthened "the suspicions of a conspiracy," the Dawn newspaper quoted its sources as saying.
"It makes no sense that personnel who were on duty did not retaliate despite carrying active firearms... This is why the perception that the rest of the guards had some inkling about Qadri's intention is gaining strength," an unnamed official told the daily.
"Every aspect is being considered," another official said.
Investigators are trying to determine whether Qadri's colleagues were only in the know of his plan to kill Taseer or if they assisted him.
Qadri had reportedly told his colleagues of his intention to kill the Governor and even said he would surrender after the act.
Sleuths are also probing Qadri's background and collecting information from his neighbours, relatives and friends following reports that he had attended several meetings and rallies organised by religious hardliners in the recent past.
Qadri often wore a green turban, which he removed only when he put on his uniform.
Qadri said he had killed Taseer for the Governor's criticism of Pakistan's blasphemy law.
He laid down his weapon and surrendered after shooting Taseer in a market in Islamabad.
Two junior officers who accepted Qadri's request to be made part of Taseer's security detail on Tuesday were among over 30 police personnel detained as part of the investigation.
However, some senior officials conceded that the junior officers may not have been aware of the bar on Qadri.
Meanwhile, a First Information Report filed by Taseer's son Shehryar Taseer at the Kohsar police station in Islamabad on Wednesday said his father had received several threats from different religious and political groups for expressing his views on important issues.
Shehryar said Qadri had murdered his father with the cooperation and assistance of certain religious and political groups.
Shehryar did not name these groups in his complaint. Two separate teams are probing the assassination.
One team is led by Islamabad's DIG (Operations) Bin Yamin and includes officials from intelligence agencies, including the ISI and Intelligence Bureau.
The Punjab government has formed an inquiry committee led by Additional Inspector General Nasir Khan Durrani which will identify loopholes, shortcomings and lapses in Taseer's security protocol.