The Pakistani Taliban's leader Baitullah Mehsud is gravely ill, his top aide has told the BBC.

巴基斯坦塔利班领导人Baitullah Mehsud的最高助手告诉BBC，Baitullah病情非常严重。

Baitullah Mehsud has been blamed for suicide attacks on Western forces

Maulan Nur Syed denied this was linked in any way to claims Baitullah Mehsud was killed in a US missile strike on Wednesday in a remote tribal¹ area.

Both the US and Pakistan earlier said their intelligence suggested Baitullah Mehsud was killed in the attack.

There were also reports of a major gun battle between potential successors to Baitullah Mehsud after the strike.

On Sunday, Maulana Nur Syed told the BBC the Pakistani Taliban leader had not been at the house that was attacked by the US missile.

But it is thought that by making this statement, the Taliban are preparing the ground for an announcement that Pakistan's most wanted man is in fact dead, the BBC's Orla Guerin in Islamabad says.

'90% certainty'

Earlier, Pakistani officials said they had "credible² evidence" that Baitullah Mehsud had been killed.

But senior Taliban commander Hakimullah Mehsud then contacted the BBC to say his chief was alive and well.

Officials in Islamabad later said that Hakimullah was himself one of those killed in a fight over succession in South Waziristan.

The BBC's Aleem Maqbool, in Islamabad, says the situation is very unclear and information is based on rumours³ from deep inside militant⁴ territory in north-west Pakistan.

In Washington, US National Security Adviser⁵ Jim Jones put he level of US certainty that Baitullah Mehsud had been killed "in the 90% category".

The Pakistani interior minister have challenged the Taliban to prove its leaders are still alive.

But Taliban commanders have dismissed this as a ploy⁶（活动，策略） to flush（淹没） them out into the open.