The police officer heading the investigation team probing the devastating suicide blasts that targeted former Pakistan premier Benazir Bhutto is expected to be replaced, officials said Tuesday.
The move is being considering after Bhutto said she had no confidence in the current chief, senior police officer Manzoor Mughal, whom she accuses of involvement in the torture of her husband.
Bhutto told a news conference on Monday that Mughal was involved in torturing her husband Asif Zardari while he was in police custody in 1999 under the government of former prime minister Nawaz Sharif.
"The provincial authorities are considering replacing Mughal and handing over the investigation to some other senior police officer," a senior police official told AFP in Karachi, the capital of southern Sindh province.
The regional Sindh government's home minister Wasim Akhtar also confirmed the change was being considered, although he did not say if the move was in response to Bhutto's claims.
"We are considering it because Mr Mughal is expected to go on leave, so there can be a new officer heading the investigation," Akhtar told AFP.
Bhutto has also written to authorities to demand that she appoint the police officers guarding her, after she claimed that the security forces and government have been infiltrated by Islamic militants.
The two-time former premier has vowed to stay in Pakistan and campaign for upcoming general elections despite twin blasts that tore through her homecoming parade in Karachi last Thursday, killing 139 people.
She has been surrounded by heavily armed security guards on each of her rare public outings in Karachi since the deadly blasts.
Investigators meanwhile confirmed that two suicide bombers were involved in the attacks, the worst such incident in the country's history.
Police last week found the head of one of the suspected bombers and released a sketch offering a five-million rupee (84,000 dollars) reward for information leading to his identification.
Another badly damaged head was found later at the scene and his face is being reconstructed with the help of forensic experts, a police official said.
Police had initially said a grenade was thrown by an unknown assailant before a lone suicide bomber detonated his explosives.
"We are baffled as to how the second bomber survived after the first bomber exploded because evidence from the scene suggests they both were on the left hand side of the road and in close proximity to each other," an officer said.
"We still have no evidence from the scene of the crime that could lead to the identity of the bombers," the officer added.
Akhtar told AFP that the blasts damaged four of six close circuit cameras at the blast site.
"Our experts are examining the footage from the remaining cameras and we have also got footage from television stations," he added.