"Work and study in Ireland", they said. "Earn Euro."

Over the following months, 12 people signed up for the Irish work-permit scheme, each paying up to 3,500 to the Mauritian private academy organising it, the Micro Data Information Academy for Excellence (MDI).

That money got them as far as the immigration booth in Dublin airport, one morning in late October 2004.

They were refused entry and deported.

Last Wednesday, the man who facilitated the Irish side of the scam, Olaitan Ilori, became the first person to be found guilty of trafficking here.

The case was complicated by the word "trafficking". As defence counsel Aileen Donnelly SC said in her summing up, "It connotes all sorts of terrible things, issues of people in sweatshops or people in the backs of lorries. None of that applies to the facts of this case."

The prosecution was not so concerned with the niceties of the connotations of "trafficking". The Mauritians had arrived at Dublin airport, were told to say they were tourists and presented a document stating they were on a "fact-finding mission". This was "meaningless gobbledygook", prosecution counsel Alex Owens SC told the jury in his summing up, and "Mr Ilori was up to his neck in it".

Olaitan Ilori's involvement dated back to around the same time the ads appeared in Mauritius. In early 2004, he was visited at his office by a Mauritian living in Ireland by the name of Doger Rose.

Ilori ran an "immigration consultancy" from an office at No 91 Parnell Street, Dublin 1, under the business name Equity Office. Rose had been retained by the MDI academy in Mauritius to help secure jobs and work permits for its clients. He asked Ilori for his help. Ilori agreed and charged Rose his basic consultancy fee of 50.

What exactly was agreed in the dealings between Ilori and Rose isn't clear because Ilori didn't testify and Rose turned out to be a very unreliable witness. He contradicted himself in the box and, on his second day of testimony, it transpired he had 11 previous convictions in Mauritius, including swindling, larceny, robbery and unlawful wearing of a police uniform. It also emerged that Rose had received an immigration stamp regularising his status in the country on the first day of the trial and had had trafficking charges against him dropped by the DPP.

But one thing verifiably passed between Ilori and Rose: money. Rose paid Ilori 16,300 in cash in June and July 2004, allegedly for workpermit applications, and Ilori gave Rose receipts.

In October 2004, Ilori travelled to Mauritius, to brief MDI's clients and to travel back with them to Ireland.

There was a meeting at MDI's offices, conducted in a mixture of English and Mauritian Creole.

According to a succession of the Mauritian witnesses, Ilori told them he had organised jobs for them in Ireland where they would do a brief "trial" and then be given their work permits.

Amongst various documents, the group were each given a "letter of recommendation" from MDI, saying they were "candidates" of MDI on a "fact-finding mission" in the Republic of Ireland to obtain "firsthand information in areas of mutual interest" such as information technology and hospitality.

Shortly before 11am on 27 October their flight touched down in Dublin. Detective garda Michelle O'Connor, an immigration officer, was "doing the non-national queue" at immigration control. O'Connor noted each of the Mauritians had open return tickets and had filled out the landing card choosing "tourism" as the purpose of their visit. (They later said they had been advised to do so by Ilori; the defence argued this was legitimate advice as there was no option for "seeking work". ) On the landing cards, the Mauritians had each written their occupation. These included "technical operator", "IT analyst", "cook", "butler" and "hawker".

O'Connor read the "factfinding mission" letter but, perhaps unsurprisingly, wasn't convinced.

She told the court, "I decided, basically, they were telling lies. I told them I didn't believe they were coming in for a holiday. I don't even believe they knew what that letter meant."

O'Connor alerted her colleagues. Ilori had already passed through immigration, but was arrested before he left the airport. He was interviewed by gardai that night. Brief clips from the video of the interview were shown during discussions in the trial about the admissibility of evidence. In one, Ilori said, "I have conscience. I give them the best of advice.

Come in. Look around."

This was the crux of the defence case: that Ilori had simply given well-meaning (though not very good) advice on how to find work in Ireland within the bounds of the law.

They could come in as tourists, "look around" (or "fact-find") and, once they had found willing employers, apply through the correct channels for the proper authorisation to work . . . or, if necessary, return home to Mauritius while a prospective employer processed a work permit.

There was a further subtlety to the defence case over the question of whether the Mauritians were ever actually "illegal immigrants".

As they were turned back at the airport and never given permission to enter, they had never become "illegal" in Ireland, the defence argued. And as Mauritians do not need visas to enter Ireland as tourists, they were entitled to seek to enter and . . . as Ilori had said . . . "look around" without becoming "illegal" until such time as they might violate their status as tourists by working.

Ultimately, the jury wasn't interested in such subtleties but agreed with the prosecution's summing up of the facts: "They are told to turn up at customs with all this documentation. They are told to say they are tourists. They are left there with no chance of getting into this country.

They are illegal immigrants and we say Mr Ilori was intimately involved in all of this, " concluded Alex Owens.

After a 12-day trial and seven hours of deliberation, the jury returned a unanimous verdict on seven charges of trafficking and a majority verdict on five charges. Judge Martin Nolan adjourned sentencing until later this month and remanded Ilori on continuing bail.