Prince Harry was moved to a guarded location during a recent Taliban attack on Camp Bastion, the Defence Secretary has revealed.
Philip Hammond had earlier told the Commons that Captain Wales - as Harry is known to the Army - was never in danger although he was present during the assault on Bastion last Friday.
He later explained that the 28-year-old is being protected by "additional security arrangements" as he carries out his second tour of duty in Afghanistan.
Speaking on BBC 2's Newsnight last night, he said: "Clearly there are fall-back plans and I can't go into the detail of them - but once we knew on Friday night that the perimeter at Bastion had been breached he would have been moved to a secure position under effective guard."
Asked by presenter Jeremy Paxman if that meant Prince Harry was not treated the same as every other soldier, the Defence Secretary said: "You asked me whether he was at any greater risk.
"And I've told you that in combat he's at the same risk as any other Apache pilot.
"Clearly if we had a VIP in theatre and frankly if I was there or, Jeremy, if you were there in Camp Bastion and there was a breach of the perimeter security, anybody who might, by nature of who they are, be a target, they would be put in a secure location."
He added: "He is serving there as an ordinary officer but clearly there are additional security arrangements in place that recognise that he could be a target himself specifically as a result of who he is."
Two US Marines were killed and six planes destroyed during the attack on the desert base in Helmand province, where the bulk of the UK's 9,500-strong force in Afghanistan are deployed.
Taliban sources claimed Bastion was targeted because Prince Harry is serving there as an Apache attack helicopter gunner.
The Prince was about two kilometres away with other Apache crew members during the assault on the base, which is the same size as Reading.
Hammond's comments came following a bloody spell for Nato forces in the troubled country, which saw two British soldiers killed at the weekend by an attacker dressed as an Afghan policeman and feigning injury.
Married father-of-two Sergeant Gareth Thursby, 29, and Private Thomas Wroe, 18, were shot dead in the south of Nahr-e Saraj district, Helmand province, on Saturday, in what appears to be the latest in a string of "green-on-blue" incidents.
The soldiers, from 3rd Battalion, The Yorkshire Regiment (Duke of Wellington's), were killed at a checkpoint when a man dressed as a local Afghan policeman pretended to be injured so they would help him.
On Friday, Lance Corporal Duane Groom, from 1st Battalion Grenadier Guards, died after his vehicle hit a roadside bomb.
The weekend's bleak news brought the total number of members of UK forces to have died since operations in Afghanistan began in October 2001 to 430.
Answering an urgent question in the Commons, Hammond insisted the strategy of "mentoring and training" Afghan army and police was vital to the war effort, adding: "We cannot and we will not allow the process to be derailed."