The British government has announced it will help in investigations into the death of former Pakistan Premier Benazir Bhutto but Scotland Yard officers said it may already be too late to establish the exact circumstances of her death.
Detectives told the British Broadcasting Corporation (BBC) that by now nearly all forensic evidence has been lost from the crime scene and there is little usable footage of the attack. It is thought that the only way to establish what actually killed Bhutto December 27 would be by exhuming and examining her body - something her family has so far opposed.
Britain's Metropolitan Police Service confirmed that it is to send a small team from its counter-terrorism branch to provide support in the Bhutto murder inquiry.
However, there is some uncertainty over who will lead the inquiry. While the Metropolitan Police said in London that Pakistani authorities would continue to lead the investigation, White House spokeswoman Dana Perino said in Washington that, "Scotland Yard being in the lead in this investigation is appropriate and necessary".
Earlier Wednesday, Pakistan President Pervez Musharraf and British Foreign Secretary David Miliband both announced Britain's agreeing to the Pakistani request.
Miliband said British Prime Minister Gordon Brown, at the request of Musharraf, "has agreed to send a UK Police team of technical experts to assist the government of Pakistan in the investigation of the death of Benazir Bhutto. The team is due to leave the UK by the end of the week.
"As the terrible events of last week show only too clearly, Pakistan faces a very serious threat from extremism. The UK is already closely engaged with the Government of Pakistan on counter-terrorism cooperation. The Prime Minister and President Musharraf have agreed to further deepen this aspect of our relationship, and officials will travel to Pakistan to take this forward."
Musharraf, in his address in Islamabad, did not repeat government claims blaming South Waziristan-based extremist leader Baitullah Mehsud, who has denied involvement in Bhutto's death.
But he appealed to the media and Pakistanis to "expose" Mehsud and another prominent pro-Taliban militant leader based in the Swat Valley, Mullah Fazlullah, whom he also accused of orchestrating suicide attacks.
The Pakistan government had initially said it did not need foreign help to probe the killing and Bhutto's widower, Asif Ali Zardari, said after Musharraf's address that Britain's involvement in the investigation was too late. He said British assistance should have been requested after an attempt on Bhutto's life in October.
Bhutto's Pakistan Peoples Party (PPP) demanded a wider United Nations inquiry after the government declared just one day after the attack that Al -Qaeda-linked Mehsud was behind the killing.
The cause of death was initially put down to gunshot wounds in the neck but the government later said Bhutto had died from a head injury, sustained when she hit a lever on the sunroof of her vehicle in the force of a bomb explosion.
A medical report seen by reporters said no surrounding wounds or blackening were seen around Bhutto's head wound. "No foreign body was felt in the wound. Wound was not further explored," it said.
However, Britain's Channel 4 television then broadcast new video footage showing a man firing a pistol at Bhutto from just metres away as she emerged from the sunroof to greet supporters. It shows her falling into the vehicle just before the explosion occurs.
Bhutto's body was buried without any autopsy after the PPP said it did not trust the government to carry out an independent examination.
Musharraf, in his nationally-televised address Wednesday, said new evidence was coming to light but that expert advice was needed, and he thanked the British prime minister for accepting his request for assistance.
"This is a very significant investigation. All the confusion that has been created in the nation must be resolved," Musharraf said.