THE 15 British sailors and marines freed by Iran arrived home yesterday to face more intensive interrogation by military UK intelligence officers than anything they experienced at the hands of Iran's Revolutionary Guard.

Just after noon, the 14 men and one woman disembarked from their British Airways flight at London's Heathrow Airport wearing uniforms flown out to them for the return journey to avoid them appearing in the civilian suits provided as farewell "gifts" by their Iranian captors.

After a brief pause for the world's cameras, the group - which included Scottish marine Danny Masterton, 26, from Ayrshire - were hurried to two RAF Sea King helicopters and flown to the Royal Marines' base at Chivenor, near Barnstaple in North Devon. There, they saw their friends and families for the first time since being captured, and had medical checks - and the debriefing process started.

It has emerged that one of the 15 - Royal Marine Captain Chris Air - admitted Britain was gathering intelligence on Iran in the Gulf, which the Ministry of Defence said was "all part of modern operations".

The reunion, after nearly two weeks of anxiety, proved too much for some as parents, brothers, sisters, girlfriends, wives, husbands and children embraced those they thought they might have lost for ever.

Leading Seaman Faye Turney, the one woman among the group, was reunited with her Plymouth-based Royal Navy sailor husband Adam, and three-year-old daughter, Molly.

Royal Marine Lance Corporal Mark Banks, from Lowestoft, Suffolk, was met by his parents Penny, 49, and Allistair, 52. Mrs Banks said: "We are delighted to have him back - it was nice to hold him again. We can't wait to have him home to see everybody again."

Mr Banks added: "We are very proud of him. He looks well but tired."

The Marines spokesman, Lieutenant-Colonel Andy Price, read a statement on behalf of all 15, which said: "It goes without saying that we are all extremely happy to be back home in the UK and reunited with our loved ones.

"Touching down at Heathrow this morning was, for all of us, a dream come true and the welcome we have enjoyed today is one none of us will forget. The past two weeks have been very difficult.

"But staying together as a team we kept our spirits up, drawing great comfort from the knowledge that our loved ones would be waiting for us on our return to the UK."

Lt-Col Price thanked the public for their support for the group during their captivity and said it meant a lot to them.

Operator Mechanic Nathan Summers said: "It is only now that we are home that we have found out just how much support we have had, and still have.It is a great relief to be back with friends and family."

It is understood that the group will be staying in the Chivenor base until today.

The seven marines and eight sailors were seized on March 23 as they carried out a routine search of a cargo ship in the northern Gulf.

The dispute, throughout their time in captivity, rested on whether they had strayed into Iranian waters.

Britain insisted they had done nothing wrong. During their detention, extensive television footage was shown of the naval personnel apparently apologising for their actions.

Prime Minister Tony Blair insisted yesterday that the release of the sailors and marines had been secured "without any deal, without any negotiation, without any side agreement of any nature whatever".

Shortly after their reunion with loved ones, the revelation concerning Capt Air was made.

In a previously unbroadcast interview, he told how one purpose of patrols in the area was to gather "int" - intelligence - on "any sort of Iranian activity". He acknowledged that he was operating close to the buffer-zone between Iranian and Iraqi waters, adding: "It's good to gather int on the Iranians."

The TV interview was recorded on March 13, but not broadcast until after the 15 had been released because of its sensitive nature.

A Ministry of Defence spokesman said: "Gathering information while patrolling is all part of modern operations. This is as true on maritime boardings as it is when a patrol is out in Basra.

"The information helps get a better picture of the security environment.

"We have said that we would not comment on the specific incident, but as we have already said, this boarding was routine."

The hostages travelled business class after their 13-day ordeal, and were accompanied by Ministry of Defence "minders". They were under strict orders not to take advantage of free champagne because they were still on duty.

Passengers elsewhere on the scheduled flight from the Iranian capital said they heard a round of applause from the section of the aircraft where the military party was kept in isolation as the flight touched down on UK soil.

All 15 will now be questioned by trained agents who want to know where they were held and details of Iranian interrogation techniques.

The intelligence team will also seek answers on how much coercion was used to persuade them to admit on Iranian television that they had strayed out of Iraqi territorial waters before they were captured.

A special forces officer told The Herald yesterday: "None of the people in the naval boarding party is likely to have been trained in resisting interrogation. With no disrespect intended, they are all relatively low-ranking cogs in the UK military machine.

"It's likely they were under standing orders to do anything necessary - short of committing treason - to defuse any situation they found themselves in.

"That would include agreeing to take part in Iranian propaganda clips if by doing so it contributed to the likelihood of them being set free. The important thing was to bring them all home safely as soon as possible.

The hostages will be given leave and allowed to spend time with their families when the military debriefing ends in the next few days.