An Afghan man who crashed a 4x4 on to the runway at Camp Bastion was working for British forces.
The interpreter was feared to have been targeting US defence secretary Leon Panetta, who was arriving at the base at the time of the incident on Wednesday.
The stolen vehicle, apparently carrying a container of fuel, burst into flames and the man later died of severe burns.
Camp Bastion is home to a large contingent of US as well as UK forces. However, it is understood the Afghan was working with the British.
There is growing tension between coalition forces and Afghan locals after the massacre of 16 people, including several children, allegedly by a US soldier in Kandahar last weekend.
The soldier's lawyer claimed today that the unnamed 38-year-old staff sergeant had been reluctant to leave on his fourth deployment after twice being injured during tours in Iraq.
John Henry Browne said the soldier had also seen his friend's leg blown off the day before the incident.
"He wasn't thrilled about going on another deployment. He was told he wasn't going back, and then he was told he was going," he said.
The lawyer added: "We have been informed that at this small base that he was at, somebody was gravely injured the day before the alleged incident - gravely injured, and that affected all of the soldiers."
The soldier is suspected of going on a shooting rampage in villages near his base in southern Afghanistan early last Sunday, killing nine children and seven other civilians and then burning some of their bodies.
The shooting, which followed a controversial Koran-burning incident involving US soldiers, has outraged Afghan officials.
Mr Browne declined to name the soldier amid concerns for his family, but said he had two children, aged three and four.
The Taliban yesterday announced it was breaking off talks on a political settlement in reaction to the massacre.
Prime Minister David Cameron played down the significance of the move.
"I think we just have to be clear that we have a plan in Afghanistan, which is to hand over to a capable Afghan army, police and government at the end of 2014," he said.
"We will do that without a political settlement or with a political settlement. That is up to the Taliban.
"Every time they appear on the battlefield they lose, and lose decisively. Their ranks of commanders have been massively depleted.
"They have the choice - a political settlement where they give up weapons and become part of Afghanistan's political future or they take this attitude and Afghanistan will take care of its own security."
But Afghan president Hamid Karzai, also angered by the rogue soldier's rampage, called for international troops to withdraw from villages and rural areas to main bases.
He said Afghan forces should take the lead for countrywide security in 2013, ahead of the planned withdrawal of coalition troops in 2014.
He told Mr Panetta in talks that the shootings in southern Afghanistan were cruel and everything must be done to prevent any such incidents in the future.
That was the reason he was demanding the pull-out from rural areas and early transfer of security.
In a statement after meeting Mr Panetta, Mr Karzai said: "Afghan security forces have the ability to keep the security in rural areas and in villages on their own."
Mr Karzai spoke as Afghan MPs were expressing outrage that the US flew the soldier suspected of the civilian killings to Kuwait when they were demanding he be tried in the country.
Mr Cameron and President Barack Obama said in Washington this week that they and their Nato allies were committed to shifting to a support role in Afghanistan in 2013.
Mr Obama gave his fullest endorsement yet for the mission shift, but he said the overall plan to gradually withdraw forces and hand over security in Afghanistan will stand.