The chief executive of Pike River mine says the families of the 29 victims of the disaster are coming to terms with the fact they may not get their loved ones back.

Asked about the hopes of the families of the 29 miners trapped inside at a press conference today, Mr Whittall said there was resignation among some that thay may not get their loved ones back as they wished they could.

When asked if the bodies could still be intact, Mr Whittall said he couldn't speculate on that as he was not a forensic expert.

However, he said the fire may be close to the shaft and the men could be about 500 metres away from the fire.

He said he was sure some families hoped "in their hearts" that there could still be someone tapping on a pipe, while others were totally resigned to the "total loss of life" and the possibility they would not get their loved ones out of the mine intact.

GAG may have to be used 'again and again'

Meanwhile, Mr Whittall said a jet engine may have to be used several times to make the Pike River mine safe for entry to recover the remains of the miners.

He hoped the GAG engine could be in place to begin pumping in exhaust gases by about midnight tonight.

The challenge was dealing with a fire inside the mine which is now being fed by loose coal and part of the coal seam in the mine.

"We may have to redeploy the GAG again and we may have to do it again and again, depending on what happens with the fire and how deep-seated it is," Mr Whittall said.

The GAG engine works by pumping gases such as carbon dioxide and nitrogen into the mine to starve it of oxygen and put out the fire.

Mr Whittall said once the GAG engine had been used, gas levels would then be monitored to ascertain when it was safe to enter.

The use of the GAG engine was delayed last night when polyurethane used to fill the void at the mine portal caught fire.

The fire lasted about an hour but set back the use of the GAG by several hours.

Liquid concrete will now be used to seal the mouth of the mine.

Mr Whittall said he was hopeful the mine could be reopened while the Royal Commission of Inquiry was still underway as long as separate inquiries by the police, coroner and Department of Labour into the Pike River incident had been completed.