Two diplomats accused by Afghan officials of making contacts with the Taleban have left the country after talks to stop their expulsions failed.
Taleban fighters in Helmand were recently forced out of Musa Qala town
One is a high-ranking British UN employee, Mervyn Patterson. The other is the acting head of the EU mission in Afghanistan, Irishman Michael Semple.
The Kabul-based pair were accused of posing a threat to national security during a visit to Helmand province.
The Helmand governor says he warned the diplomats not to meet the Taleban.
The BBC's Alastair Leithead in Kabul says it has become clear that parts of the Afghan government knew Mr Patterson and Mr Semple were in Helmand and had been meeting tribal elders, so there has been some confusion over the government's decision.
As yet, there has been no explanation from the foreign or interior ministries as to exactly why the men were told to leave.
However, the governor of Helmand province Asadullah Wafa said he had warned the diplomats not to meet the Taleban who are "fighting us and training suicide bombers".
"I asked Michael (Semple) 'Why are you coming here?' and he said 'I have come to see the Taleban and speak with the Taleban as part of the ongoing process," Mr Wafa told journalists in Helmand.
"I told Michael the information I have about you is that you are supporting those people who right now are really fighting the government. I said that I am the governor of the province and you should share this information with me.
"I had told him three or four times to bring permission from the government and asked him 'Why are you meeting the Taleban and what will you talk to them about?' He just laughed and said nothing. After that I spoke to the central government and they said they had not given (the diplomats) any permission."
Mr Wafa also told the BBC's Pashto service that an Afghan travelling with them had almost $20,000 (£10,000) on him which he could not explain.
A number of Afghan nationals are still being held by the intelligence service in connection with the incident.
Meanwhile efforts are continuing in the hope that Mr Patterson and Mr Semple, widely considered as two of the most respected and knowledgeable international experts on Afghan affairs, will be allowed to return to the country.
The United Nations has argued that the expulsions are a result of a misunderstanding.
"We were in Helmand province to talk to the people on the ground," UN spokesman Aleem Siddique said, the Associated Press news agency reports.
Mr Siddique said the aim of the talks was "to understand from the people on the ground what their needs are, what their concerns are and that includes people who are perhaps less than supportive of the government of Afghanistan".
An EU official in Brussels told the BBC News website: "It was a misunderstanding and is not officially an expulsion." He said the work of the EU in Afghanistan would not be affected.
Despite UK Prime Minister Gordon Brown's insistence that Britain does not negotiate with the Taleban, local-level talks are seen as a vital part of the strategy to bring peace and stability to Afghanistan, our correspondent says.