It was the deal of deals. Four years ago, a landmark site fronting onto the Stillorgan dual carriageway in south Dublin was sold for €31.75 million. Just a fortnight ago, the 11.3 acres sold for more than €85 million.

The price paid by Glenkerrin Homes fell shy of the €100 million mooted by some market insiders when the sale began, although the land at the Grange near Galloping Green yielded the highest price yet obtained for a development site in Dublin.

Two weeks before the property was put on the market by CB Richard Ellis Gunne, an Bord Pleanála granted permission for 478 apartments, a nursing home, offices and shops.

That permission cleared the way for a remarkable return on an investment led by financier Mr Derek Quinlan. But with five residents groups objecting to the proposed scheme, it took two applications to Dun Laoghaire-Rathdown and two appeals to An Bord Pleanála before the all-clear was received.

A former Revenue official, Mr Quinlan has established quite a reputation at the high end of the investment market. After years of low-profile operations, his company Quinlan Private has developed a formidable presence in the Irish and British property markets.

While he had a personal stake in the investment at the Grange, the other investors included some of the best-known figures in Irish business and senior professionals from the legal and medical worlds.

A London-based spokesman for Mr Quinlan declined to comment on the deal yesterday. "We have no comment on this or any list. We never discuss the identity of our clients," he said.

However, mortgage records indicate investors in the project include the former Elan executive, Mr Donal Geaney, who is chairman of the Irish Aviation Authority and chairman of the National Pensions Reserve Fund.

Other investors included Mr Geaney's former colleague in Elan, Mr Séamus Mulligan, and the senior Davy stockbroker, Mr Kyran McLaughlin. Mr Mulligan declined to comment yesterday when asked about the deal.

While the mortgage records do not break down the size of the individual shares in the project, a document from March 18th this year indicates that the Brooklawn Property Holding Company was involved in the project.

Brooklawn is linked to the construction firm G&K Crampton, whose joint managing director, Mr David Crampton, is listed as a chargor in the other two mortgage records.

Other individuals who are listed in the documentation include the businessman, Mr Finn O'Sullivan, who sold his Irish Express Cargo logistics firm for some €82 million in 2000.

The consortium also included Mr Paul Anderson of the Dublin Cinema Group. Another investor was Mr Brendan O'Mara, chairman of the chartered surveyor and project management firm, the Bruce Shaw Partnership. Mr O'Mara was a supporter of the former Minister for Foreign Affairs, Mr David Andrews.

Legal figures in the consortium include the barrister Mr John Gordon SC and the solicitor Mr Dan E O'Connor, who is a partner in Arthur Cox, one of the biggest law firms in the State.

Mr O'Connor, who also declined to comment yesterday, is a specialist in property law and commercial property in particular.

Medical figures listed as chargors in the mortgage documentation include the Master of the National Maternity Hospital, Dr Declan Keane.

Others included the obstetricians Dr Peter McParland and Dr Peter Boylan, and the cardiologist Dr Peter Crean.

Two other individuals also feature in the mortgage documentation. They were Mr Francis Brennan of Killarney, Co Kerry, and Mr Patrick Mooney of Maynooth, Co Kildare.

It is not known whether any of these individuals were involved in Mr Quinlan's most celebrated deal, in which he led a £750 million buy-out by Irish investors of the Savoy Hotel group in London.

But if that particular arrangement suggests that the boom years have left many Irish with big money to spend, the Galloping Green deal shows that the domestic property market is still proving to be a bonanza for savvy investors.