Irish Special Branch officers made an attempt to enter the house in Monasterevin but were forced to retreat when shots were fired and the kidnappers barricaded themselves in an upstairs bedroom.

A senior detective at the house said: "At one point we could see him with a pistol held to his head in the window and every time we made a move he shouted 'For God's sake don't come near. They will kill me'."

Dr Herrema, chief executive of the Dutch-owned Ferenka factory in Ballyvarra, County Limerick, was abducted on his way to work on 3 October.

One of his kidnappers has been named as 28-year-old Eddie Gallagher. He has been wanted by police since his escape from Portlaoise jail in 1974. His accomplice is believed to be his 21-year-old girlfriend Marian Coyle.

They have demanded the release of three Republican prisoners - Rose Dugdale, Kevin Mallon and Jim Hyland - in return for Dr Herrema's safety.

The siege started following extensive questioning of two brothers who were stopped while driving Mr Gallagher's car. It is believed the brothers gave clues of the whereabouts of Dr Herrema.

Officers are thought to be using the house next door to set up a bugging device so they can hear what is going on.

No deal

Both sides appear to have adopted a wait-and-see approach, with Irish police not wanting to risk Dr Herrema's safety by storming the house.

A spokesman for the Irish Government said there would be no negotiations and no deal with the kidnappers.

But the kidnappers could be hampered by a lack of food and water. No supplies have been provided but police said they would not turn off water supplies to try to end the siege.

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