Just before Christmas 2005, one of the backers of private equity investment company RQB was having lunch with a group of developers and property advisers in what was then Jean Christophe Novelli's restaurant in La Stampa on Dawson Street in Dublin.

It was one of two tables occupied that lunchtime, a portent perhaps that the restaurant wouldn't remain open much longer. After lunch I congratulated the RQB backer on the acquisition of 17 acres of residential zoned land at Diswellstown in Castleknock, Dublin 15 for €25m but he told me a site they had bought at Naas Road would prove much more successful.

His observation proved prescient. A year later the Naas Road site was sold on and investors who had taken out interest-only loans made a pre-tax profit of about €200,000, having paid just €6,000 to fund the deal for a year.

Last week the company behind the Diswellstown site went into receivership, as did one involved in a site in Malahide. RQB, through a spokeswoman, declined to comment other than to confirm the moves.

David Carson of Deloitte was appointed examiner for both companies by Bank of Ireland on foot of debentures granted by it to the RQB vehicles. A receiver takes possession of all assets charged under the debenture, disposes of them and then pays the debt owed to the bank. However, they may also keep the business as a going concern with a view to selling it.

RQB's struggles are symptomatic of a wider malaise in private equity companies, particularly those that invested in land which produces no income. With land and property values down significantly across the world, Irish high-net-worth investors are feeling a significant pinch and many will now face unexpected cash calls to plug the gap between the amount invested and the property's value.

Banks will also suffer as, in many cases, the loans given to the private equity companies were on a non-recourse basis. The private client divisions of the Irish banks in particular often used this method of raising finance.

RQB was set up by Paddy Kelly and his family, along with businessman Niall McFadden, and raised money on a site-by-site basis with a minimum investment of €100,000. It charged a fee of five percent of the equity raised, a transaction fee of two percent on acquisition costs and a minimum quarterly development fee of €75,000. The money raised was then geared up to acquire sites. It also charged a success fee of 30% if investors achieve an annual return of more than 10% on their investment.

Earlier this year the Sunday Tribune revealed that RQB's three Dublin projects – the third site is in Pelletstown – were "suffering from market and banking difficulties… In each case, we are of the view that investors generally do not have either the liquidity or appetite to allow for a successful fundraising to deal with banking issues Therefore we are working with our banking partners to stabilise the situation and look to a development solution that does not result in our investors being defaulted under their co-ownership agreements. However, at this stage, the banks are in the driving seat". The detail was in a letter sent by RQB to investors.

The letter also stated that the Kelly family had reduced their involvement in the company and that McFadden and chartered accountant Declan Cassidy had provided "significant working capital" for the restructuring of the company. McFadden and Cassidy committed to supporting RQB "for as long as its bankers and investors support the business".

The Malahide site had been the subject of talks with both investors and bankers since at least November when RQB told this newspaper that in "the current climate, where banks are no longer rolling up interest, the developer and investors are looking at strategies to fund the interest payments and negotiations are ongoing between the company, the investors and the banks on that basis".

RQB's other sites are unaffected. It is best known for plans for a $900m hotel and leisure complex at Sawgrass in Florida. The letter sent this year said RQB might need to raise more funding for its developments there despite having made $8m worth of cost cuts. It had bought the hotel for $200m, almost half of which came via equity raised from high-net-worth investors in Ireland.