An incident which claimed the lives of a Westcountry-based Royal Marine, a female British Army medic and an off-duty Afghan policeman remained under intense scrutiny last night.
Corporal David O'Connor, 27, who was serving with 40 Commando from Taunton, died after being injured while on patrol in Afghanistan along with Channing Day, 25, of the 3 Medical Regiment, on Wednesday.
An Afghan man, believed to be an off-duty member of the police force attached to a local patrol base, also died in the exchange of gunfire.
The patrol came under fire near the village of Char Kutsa and, during the firefight, Corporal O'Connor and Corporal Day were fatally injured.
A statement released by the family of Corporal O'Connor, who lived with his mother in Havant, said: "David's family and friends are greatly saddened by his loss and hope to be left to grieve privately."
The family of Corporal Day said in a statement: "Channing was bubbly, sporty, beautiful and lived her life for the Army. She has died doing what she lived for and in the life that she loved."
Earlier, there were conflicting reports of what exactly happened.
The MoD said it was still unclear what provoked the shooting and could not rule out that it was another "green on blue" incident, a term used to describe an attack on coalition troops by their supposed Afghan allies.
A Ministry of Defence spokesman said an investigation was under way.
"The facts that we know are that there were three fatalities, a Royal Marine and a soldier and an Afghan man.
"The Afghan man was not part of the patrol and he was not in uniform. We do believe he was an Afghan policeman and a statement from the Afghan police has confirmed that.
"We do not know whether it was an insider attack and we do not know yet who opened fire on whom."
Investigators were yesterday attempting to establish the sequence of events, however delays are believed to have occurred because witnesses involved in the patrol have been injured themselves.
But then the Taliban claimed the deaths were as a result of an Afghan firing on the British troops in the latest insider attack which have sown mistrust between supposed allies.
To add to the confused picture, an Afghan police official said the firefight was a case of mistaken identity.
Farid Ahmad Farhang, a spokesman for the police in Helmand, said two British patrols had been in the area and one had stumbled upon an Afghan policeman washing for prayer at a stream.
They had mistaken him for a Taliban fighter and shot him dead. The firing had caused the other patrol to fear it was under attack and had opened fire, accidentally killing the two British, he claimed.
Members of 40 Cdo last month began their third tour of duty in Afghanistan. The unit's last deployment in 2010 saw 14 lives lost. A total of 435 British servicemen and women have been killed in the country since 2001.