One in twenty Irish residential mortgages is now in arrears, and the number of people falling behind on mortgage repayments has risen again in the second quarter of the year.

Since the Central Bank started collating this information in September 2009 the level of Irish mortgage arrears has increased by a remarkable 38.7 per cent.

While more than 1,000 homeowners fell into arrears of 90 days or more for the first time during the second quarter, the number migrating to long-term arrears grew by almost 3,000. Some two-thirds of total arrears, or 24,797 mortgages, were more than 180 days in arrears at the end of June.

The latest statistics also point to a slight increase in the number of people voluntarily surrendering their properties, up to 66 from 64 in the first quarter.

However, for many mortgage holders handing over the keys of the property is not necessarily the end of the problem, because until the property is sold, many still have obligations to the bank and can be charged interest as well as the cost of insurance and repairs carried out on the property.

Additionally, if the sale price does not match the value of the outstanding mortgage, homeowners can become liable for the shortfall.

Worryingly, the Central Bank figures do not give a full picture of the true scale of the difficulties, as they do not take into account the number of people who have rescheduled their mortgages, or worked out an arrangement with their lender.