Minister for Foreign Affairs Micheál Martin has warned Irish people heading abroad over the holiday season not to use passports that were reported lost or mislaid but subsequently found.

Last year there was a near 50% increase in the number of Irish citizens delayed at international borders because they used recovered passports which showed up on a list of stolen passports.

Martin said that last year Interpol, the international police force, contacted the passport office concerning 126 incidents in which it sought to verify the identity of an Irish citizen using a passport that was recorded as being lost or stolen.

This compares to 87 such incidents the previous year.

The passport office was able to resolve such cases after checks of the relevant passport details against its own database were carried out, the minister said.

The increase in such incidents last year is due in part to the heightened security at international ports and airports and an increase in the number of border stations worldwide that are electronically reading passports, Martin said.

Of the 34,622 Irish passports which went missing last year, 29,801 were lost or mislaid while 4,821 were reported stolen.

This is a drop on the 36,264 passports lost, mislaid or stolen in 2008.

Last year, the passport office issued 580,000 passports.

Martin said that since October last year, the Department of Foreign Affairs reports the serial numbers of lost or stolen passports to Interpol daily.

"This information is than made available immediately to police forces worldwide in the Interpol database to protect against the fraudulent use of these Irish passports," he said.

Martin reminded Irish citizens who report a passport lost or stolen that they give an undertaking not to travel on a missing passport if subsequently found.