The initial explosion during the Pike River coal mine disaster in New Zealand last year possibly killed the 29 miners trapped underground almost instantly and those who first survived eventually died within minutes as the blast created a condition that humans would not withstand.

These have what emerged basing on testimonies gathered on the first day of the inquest looking into the November tragedy, which also claimed the lives of two Australian miners following the series of explosions in the coal mining site.

Police Superintendent Gary Knowles told the inquest panel that medical and mine experts informed him that the miners were immediately subjected to excruciating conditions of asphyxiation, carbon monoxide poisoning, extremely high temperatures of up to 2000 degrees Celsius and trauma from the first explosion.

Knowles said that the experts visited the disaster site five days after the initial blast and concluded that such extreme condition would almost automatically kill most of the trapped miners.

Also, low oxygen levels beneath, which the experts said could have reached levels of one to eight percent, would render the trapped men immediately unconscious. They added that death would have followed within five minutes.

All miners could have been dead by the time ensuing explosions were heard in the mining site, according to the inquest panel.

The ongoing inquest is headed by New Zealand's chief coroner though its coverage has been capped for now to provide leeway for a possible royal commission into the disaster.

Main objective for the inquest panel at this time is to identify the victims and determine their cause of death to facilitate for the proper issuance of their death certificates. Also, the operation for recovery of the miners' remains is still underway.