believing allegations in the secret military logs of the Afghanistan conflict published earlier this week.

The leaked documents suggest that the ISI, one of Pakistan's two military intelligence agencies, was encouraging the Taliban as recently as last year.

Wajid Shamsul Hasan, Pakistan's high commissioner, wrote: "One would have wished that the prime minister would have considered Pakistan's enormous role in the war on terror and the sacrifices it has rendered since 9/11.

"There seems to be more reliance on information based on intelligence leaks which lack credibility of proof. A bilateral visit aimed at earning business could have been done without damaging the prospects of regional peace."

The prime minister initiated the row this morning in a speech to Indian business leaders in Bangalore, when he spoke of his horror at thein the past of the terror threat from Pakistan, though ministers have restricted themselves to criticising Pakistan for tolerating terror groups. But the prime minister's language came close to endorsing the Indian view that authorities in Pakistan have a hand in the terror.

Cameron named several terror groups which are, according to India, sponsored by Pakistan. "We – like you – are determined that groups like the Taliban, the Haqqani network or Lakshar-e-Taiba should not be allowed to launch attacks on Indian and British citizens in India or in Britain."

Downing Street insisted the prime minister was not accusing Pakistan's government of sponsoring terrorism. But a few minutes after his speech, Cameron made clear that official agencies in Pakistan were responsible for harbouring terrorists.

Asked on the Today programme whether Pakistan