UCD economist Morgan Kelly has said there were 11,000 mortgages of over €500,000 taken out between 2006 and 2009 with an estimated value of €9 billion.

Prof Kelly has published a working paper on large Irish mortgages following an Irish Times article he wrote entitled ‘Interest-only mortgages depended on a rising market and now many in the small-time landlord sector smell trouble’.

In it he said that ‘the interest-only candy pot was also raided by an estimated 10,000 accountants, lawyers and other professionals who spent between €1m and €2m each on buying homes with a typical loan-to-value mortgage of 80%.’

In his working paper Prof Kelly uses Department of Environment data on the number of mortgages and their size.

He said: ‘We estimate that from 2006 to 2008 there were fewer than 2,000 loans over €1m with total value of €3 billion; and that there were 11,000 loans over €500,000 with estimated value of €9 billion.

‘While the number of people taking out these mortgages is unknown, the conjecture that the largest 10,000 mortgage borrowers owe around €10 billion, largely for buy-to-let mortgages, does not appear implausible given these results.

‘More tentatively, an ecological inference procedure suggests that interest-only mortgages went almost exclusively to property investors.’