The party of the slain Pakistani opposition leader, Benazir Bhutto, is demanding the United Nations lead the investigation into Ms. Bhutto's assassination. But the Pakistani government insists a Scotland Yard investigative team arriving to help in the probe is sufficient to solve the controversy surrounding her death. VOA's Nancy-Amelia Collins reports from Islamabad.

The Pakistan People's Party, Ms. Bhutto's party, says a United Nations investigation into her death it is the only way to get at the truth.

The government has requested help from Britain's Scotland Yard. But Sherry Rehman, a PPP spokeswoman, says the death of someone of Ms. Bhutto's stature - she was twice prime minister of Pakistan - warrants a credible investigation.

"The party's asked for a U.N.-led credible investigation, independent investigation…We feel that it's a large enough disaster and tragedy to mark the death of a prime minister who had said she was threatened constantly," said Rehman. "She had appealed to the Pakistan government repeatedly, very specifically, for particular support in terms of her security, which she did not receive, right till the end."

Ms. Bhutto was assassinated in the city of Rawalpindi a week ago while campaigning for parliament. Her death sparked riots across this nation, leading to more than 50 deaths and millions of dollars in property damage.

The former prime minister had complained repeatedly about a lack of security. She narrowly escaped a suicide attack the day she arrived back in the country last October, after eight years in self-imposed exile.

Before her death, she said elements within the government were trying to kill her. The government denies that charge, but there is no disputing that controversy surrounds the assassination.

Television footage shows a man alongside Ms. Bhutto's motorcade firing three shots at the back of her head. The back of her hair and her veil are lifted, and then she slumps down in the car. An apparent suicide blast follows.

The government, however, says Ms. Bhutto did not die from a gunshot. It says the force of the blast caused her to crack her skull on her car's sunroof as she ducked the attack. The government blames al-Qaida for her death.

Ms. Bhutto's supporters say the government is at least partly responsible because it failed to provide adequate security. Others simply accuse the government of carrying out the assassination.

No matter who leads the investigation, it is questionable how much evidence is left. Shortly after the attack, local television showed blood and debris being washed from the attack site, destroying potentially crucial evidence.

Political analyst Nasim Zahra says she doe not believe investigators will have much evidence to work with.

"Most of the evidence has kind of disappeared, plus of course the family's not going to let the body be exhumed, understandably, so beyond then just kind of talking to people and questioning those who were involved at the site of the crime itself," said Zahra. "I mean I don't think you can have an exhaustive inquiry."

President Pervez Musharraf announced Wednesday that the parliamentary elections scheduled for January 8 would be delayed until February 18, saying the riots had damaged polling centers and destroyed voter lists.