British intelligence officers have been blamed for bringing an impostor to take part in peace talks with Afghan president Hamid Karzai, under the mistaken impression that he was a high-level Taliban commander.
Mr Karzai's chief of staff Mohammad Umer Daudzai told the Washington Post that an Afghan at the meeting realised that the man was not who he claimed to be, and he was later uncovered as a shopkeeper from the Pakistani town of Quetta.
Mr Daudzai said that Britain and other European countries "are in haste" to promote a peaceful settlement in Afghanistan so their troops can be withdrawn, and said that foreigners were getting too "excited" about potential breakthroughs.
"This shows that this process should be Afghan-led and fully Afghanised," said Mr Daudzai.
"The last lesson we draw from this: International partners should not get excited so quickly with those kind of things. Afghans know this business, how to handle it. We handle it with care, we handle it with a result-based approach, with very less damage to all the other processes."
Meanwhile, The Times claimed that MI6 paid hundreds of thousands of pounds to the man in order to keep the talks on track.
The paper quoted an unnamed Afghan Government official as saying that "naive" British intelligence agents believed the man's claim to be a minister from the former Taliban regime who was in a position to negotiate on behalf of the fundamentalist movement.
Both Downing Street and the Foreign Office declined to comment on the reports, saying that they would not discuss "operational" matters relating to intelligence.
According to The Times, MI6 agents in Pakistan believed they had made a breakthrough after making contact with a man claiming to be Mullah Mansour, second only to Mullah Omar in the Taliban leadership. A meeting with Mr Karzai in Kabul was arranged in July or August, attended by British officials.
Mr Daudzai said that it was at this meeting that an Afghan recognised the fake Mansour was not who he claimed to be. Afghan intelligence later established he was no more than a shopkeeper, he said. The Times quoted an Afghan government official as saying: "British intelligence was naive and there was wishful thinking on our part."