An aerial view of emergency services people working at the ruined CTV building in central in Christchurch, New Zealand - 100 people are believed to trapped beneath the rubbleAP

Read more: Two Irish killed in N.Z quake, three still missing

The Irish Government has strong concerns over two Irish people still missing following the earthquake in Christchurch, New Zealand. The Department of Foreign Affairs has been unable to contact nine Irish people in the city, with two being of particular concern.

It has been confirmed that one Irishman died in Monday's earthquake which measured 6.3 on the Richter scale. In total 75 people have been confirmed as dead while 300 others remain missing.

The hope of finding more survivors of the earthquake is quickly fading as rescue crews sift through the rubble in the New Zealand city. The exhausted New Zealand crews are now being joined by hundreds of foreign volunteers.

The Director of New Zealand's Ministry of Civil Defence and Emergency Management, John Hamilton, warned that the rescuers only have a window of two or three days to find people alive after the quake.

Attempts to find anymore alive in the collapsed Canterbury Television (CTV) building have been abandoned. Those missing inside the city center building include foreign students from a language school. It's believed that up to 100 of those missing in Christchurch are in the CTV building.

The police are also warning that city centre 26-story hotel is likely to collapse which could create a 'domino effect' on the surrounding structures.

Mayor of Christchurch, Bob Parker, said the city was now facing hard decisions about rebuilding the center of the earthquake-prone area.

Speaking to New Zealand television he said "We are not going to walk away from this place…We may have to level entire blocks in some places."

The Irishman who died has been identified as Owen McKenna, in his mid-40s from County Monaghan. He was married to a woman from New Zealand and had two children. The hospital where McKenna worked contacted his family to tell them he had not arrived to work. His car had been crushed by debris.

The Irish Government is also providing assistance to and Irish woman whose British husband was killed in the earthquake.

Read more: Two Irish killed in N.Z quake, three still missing