It was still dark on a muggy morning on Monday when the Florida Joint Terrorist Task Force raided an apartment in the affluent Fort Lauderdale suburb of Weston, and a motel room in stylish Boca Raton a few yards from the beach.

The catch was three Irish people now accused of unlawfully exporting guns, using the US Mail for this and conspiracy. By the end of the week the US Assistant Attorney here, Richard Scruggs, was claiming that the operation was ordered by the IRA, which had lost patience with the Northern Ireland peace process and was building up its arsenal for renewed violence.

In the police car taking Cork-born Siobhan Browne from the apartment in Weston which she was sharing with her boyfriend, Anthony Smyth, from Belfast, she kept asking why she was being dragged away "in the middle of the night". She was told it was because of the 16 guns she had recently bought.

In the Buccaneer Motel in Boca Raton where Conor Anthony Claxton from Belfast was arrested, the FBI found 10 handguns, three of which were in packages ready to be mailed to Ireland. The FBI had already evidence that he had earlier this month mailed seven packages with 20 guns to addresses in Ireland. They also found an air ticket for him to return to Ireland in two days' time.

Now he faces 105 years in prison on the current charges and there may yet be more. He told the FBI it was lucky to get him just before he would have been out of its clutches. In a cottage in west Galway, the Garda arrested his brother and girlfriend and found some of the guns sent from the US.

Scotland Yard had learned of the gun running when some of Mr Claxton's parcels, labelled as toys, baby clothes and stereo equipment were X-rayed and intercepted at Coventry West Midland Airport on July 6th. Time was running out for the Florida trio.

At the hearing on Thursday when the three were refused bail on grounds that they were dangerous and likely to flee the US, it was revealed that Mr Claxton had claimed he was acting on the orders of the IRA and not a splinter group, as had been generally assumed given the amateurish nature of the gun-running operation.

In the court, Mr Claxton (26), slightly built and wearing glasses, did not show emotion when Assistant US Attorney Richard Scruggs said that he had told FBI agent Mark Hastbacka that he was a member of the IRA and was on a weapons procurement operation. The weapons would be used against British troops, RUC members and Protestant paramilitary groups, he is alleged to have told Mr Hastbacka who did not tape the interview but made notes.

Siobhan Browne, according to the FBI, admitted she knew Mr Claxton was "affiliated to the IRA" while claiming to have "no political views" herself.

The FBI is finding it hard to pin down who Siobhan Browne really is. In court she appeared as a tall, attractive red-haired woman in her 30s with a sharpish profile and a watchful look.

But it emerged that she has multiple identities. She has two passports, two social security cards and two driving licences, all with variations of her name and her married name of Rapaport. Her husband, Meir Rapaport, from whom she has been long separated, is also in custody as a "material witness" and is said to use numerous names. She has also used postal box addresses in the New York area as well as in Fort Lauderdale to avoid revealing where she lived when purchasing guns, which is not illegal in the US.

Just six months ago Siobhan Browne, who also had a real estate agent's licence, was working as a stockbroker and financial adviser with the prestigious firm of Morgan Stanley Dean Witter in Fort Lauderdale. She also acted as secretary for the Boca Business Network of high-flying businessmen who meet weekly to discuss how to get richer. One of them joked this week after hearing of her arrest that she should have advised her clients to invest in Smith and Wesson, the gun manufacturers.

About six months ago Ms Browne suddenly left her job with Dean Witter, telling her employers she had inherited a fortune in Ireland. She would not have to work for a living anymore, it seemed.

But it was also around this time that she was detected by the Federal Alcohol, Tobacco and Firearms (ATF) agency as buying an unusual quantity of handguns. While this was not illegal it was showing up on the ATF records on the basis of information filed by gun dealers in the area, so she was put under surveillance. Later, the ATF found that the FBI was also tracking her movements, following the interceptions of guns at Coventry airport.

It was around this time too, that fellow tenants in the Boca Raton apartment complex noticed that Ms Browne and her boyfriend were having loud quarrels after drinking sessions when they returned to her apartment. The assistant manager at the complex told this correspondent that she once witnessed Ms Browne being assaulted by Mr Smyth in the car park as they quarrelled. The manager also said that Mr Smyth claimed to be a police detective. When the manager's office objected to Mr Smyth staying in Ms Browne's apartment, which was contrary to her lease, they both left. They then went to live in his apartment in Laurel Drive, in the affluent suburb of Weston, in a complex with its own swimming pool and surrounded by country clubs. It was here they were both arrested last Monday.

The coverage of their first court appearance with Mr Claxton by the local Sun Sentinel made headlines in Ireland and Britain. Sun reporter John Holland began his report: "Three local supporters of the Irish Republican Army were arrested Monday and charged with conspiring to ship dozens of shotguns, handguns and automatic rifles to Northern Ireland, federal officials said."

The last paragraph read: "The guns were being purchased for something Browne, Smyth, her boyfriend, were `very devoted to'. A source close to the investigation confirmed the cause was the IRA."

The rival Miami Herald found the IRA connection far-fetched. Reporter Larry Lebowitz wrote: "The Broward-based ring of gun runners busted this week will not be mistaken for the sophisticated terrorists responsible for more than three decades of bloody strife in Northern Ireland.

"The group left behind an easily traced trail of receipts, serial numbers, unretrieved guns and post office security videos that by late Tuesday resulted in the arrests of four in South Florida and Philadelphia and the detention of three others in Ireland."

But by Thursday, the FBI assertion that Mr Claxton had claimed he was on an IRA-authorised arms procurement mission because the Northern Ireland peace process had "failed" was reported around the world. If the IRA was not just refusing to decommission its existing arsenal but was now buying in new, high-powered weapons, there seemed little hope for the survival of the peace process.

Ms Browne might have told the FBI she had no ties to political organisations but when she went shopping for guns from Edward Bluestein, owner of Big Shot Firearms last April, she hinted strongly there was a "cause" that needed these weapons.

On April 28th she came to Mr Bluestein's home with Mr Smyth to collect the five guns she purchased from him three days earlier at a gun show. The FBI affidavit says that: "During a conversation which lasted approximately two hours, Browne told the firearms dealer that she was looking for someone she could trust and that she was interested in purchasing as many guns as he could supply. She also stated that the guns were being purchased for something that she and her boyfriend were `very devoted to'."

Mr Bluestein also told the Miami Herald: "They wanted heavy stuff. . . they didn't tell me what they were up to. Don't get me wrong. I'm not stupid. They had Irish brogues. But I didn't think it had international implications until the end."

He also said that Ms Browne explained her reticence by saying "The more you know, the more dangerous it is for you."

Another man who sold a Magnum handgun to Ms Browne through an advertisement found her impressive. "She was a big, tall woman and she was wearing a green huntingtype vest. She looked like she could have been into shooting or hunting. So I didn't think much of it. She did most of the talking and just paid $290 for the gun. She didn't bargain at all."

One person who is amazed at this interest in guns by Anthony Smyth, while humiliated by his liaison with Ms Browne, is his wife Regina. She separated from him earlier this year when he began to drink heavily and stayed away on what he said were business trips but now appear to correspond to his moving in with Ms Browne in her Boca Raton apartment.

Regina Smyth, who is American and was tracked down by the Sun-Sentinel, said that Mr Smyth had left Belfast in the late 1970s and joined his sister, who was working for the British consulate in Venezuela. He came to the US in the mid-1980s where he worked as a second-hand car broker. Mrs Smyth, who may sue for divorce, said that her husband had told of his bitter experiences in Belfast as a Catholic. "The conditions were just terrible; they couldn't get jobs and were treated like second-class citizens. But I never, ever saw him get really angry about it. He was a pacifist really, so this is unthinkable."

It must seem unthinkable to the three sitting in cells in a federal prison in a sweltering south Florida when they should have been in Ireland.

The FBI, the ATF and the local police are all still investigating the gun-running operation which authorities now say could involve up to 100 weapons. Every contact the three defendants had is being scrutinised. There may be more arrests.

A fourth defendant, Martin Mullan, who is also accused of mailing back to Ireland guns purchased by Ms Browne and Mr Smyth, will be extradited from Pittsburgh to Florida in the coming weeks. He is said to be in the US illegally as he has overstayed his tourist visa waiver.

Ms Browne faces extra legal jeopardy from her ex-husband, Meir Rapaport, who is suspected of allowing her to use his warehouse to store parcels which have not yet been examined. Court documents say that he told FBI agents that "he knew Browne was involved with" the IRA, the Miami Herald reported yesterday.

The US State Department has an official involved in the case, showing that there is an awareness of the implications for the fragile peace process. The White House is also watching events in Florida anxiously. A spokesman, Mike Hammer, said that: "We here strongly condemn any effort to enhance the capacity for violence in Northern Ireland. We call upon Irish republican leaders to disavow any links to these events."

This is the big question. Will the IRA disavow this gun running operation gone badly wrong in sunny Florida? Can it disavow it and Conor Anthony Claxton who says he was carrying out IRA orders, according to the FBI?

The FBI will recall that it was just 10 years ago in Florida that one of its informers, Alan Budoff, was approached by IRA members Kevin McKinley and Seamus Moley from Crossmaglen who were trying to procure Stinger missiles to shoot down British army helicopters in south Armagh. They too ended up in prison.

In court on Thursday the deeply-tanned Anthony Smyth was swinging nonchalantly in his chair, letting it tip backwards, when the FBI agent behind kicked it back into place. Mr Smyth looked around with surprise at the unsmiling agent who had reminded him just where he is. Facing long years in prison if Attorney Scruggs wins his case.