A question mark hangs over who carried out the assassination of Benazir Bhutto.

Pakistan's Interior Ministry has accused al-Qaida of plotting her death, but reports suggest militant leader Baitullah Mehsud denies involvement.

The Pakistani government has released a video which it says shows the moment the former prime minister was assassinated.

She was killed in a gun and bomb attack as she left an election rally in the city of Rawalpindi.

Mr Cheema has revealed that Ms Bhutto was killed by the force of the explosion which crashed her head against a lever on the sun-roof of her vehicle and not by a bullet or shrapnel.

But a close aide who prepared her body for burial said she was shot in the head, dismissing as "ludicrous" the government theory.

Sherry Rehman, a spokeswoman for Bhutto's Pakistan People's Party was in the car behind her at the end of a political rally when an attacker fired shots at the opposition leader and then blew himself up.

"She has a bullet wound at the back of her head on the left side. That was a very large wound, and she bled profusely through that," said Rehman, who suffered a severe whiplash and leg injuries as the blast threw her out of her car.

The bomber struck when Bhutto was leaving the rally and she stood up out of her bullet-proof vehicle's sun-roof to wave to supporters just outside the venue.

Three shots were fired and the blast then went off as Bhutto was ducking back inside the car.

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