Derek Quinlan, Ireland's best known international property investor, faces huge costs on refinanced mortgages AIB loaned to him to buy a mansion on the exclusive Cap Ferrat in 2006, just weeks before the collapse of the global property market, the Sunday Tribune can reveal.

Quinlan left the south of France to live in a small town in Switzerland last year.

Emails sent by an accountant to a legal adviser last year, and mortgage filings publicly available in Nice, show that the loans and other debts on Quinlan's Cap Ferrat mansion, called La Villa Carriere, ballooned from €48m when AIB held the mortgage charges to almost €64m in April last year.

The Monaco branch of Barclays Bank had by that time taken on three loans linked to a Quinlan company that owns La Carriere.

Other public filings show:

* A planning dispute over 167sq m of the estate

* Annual interest payments of at least 6.5% on refinanced loans in 2008

* A 3% annual property tax, suggesting the villa costs almost €2m a year in levies alone

* The company owning the villa was valued at €65m last year

* An email sent by a chartered accountant in April last year detailing the debts of the company as a €48m loan to Barclays, a €5.58m loan to Barclays, a third loan of €280,000 to Barclays and a €9.97m payment in a bank account

In recent weeks, Quinlan has put one of the three houses he owns on Dublin's Shrewsbury Road on the market at an asking price of €7.5m.