Wellington, Nov 28 (DPA) It will be weeks before the bodies of the 29 men who died in a New Zealand coal mine disaster can be returned to their grieving families, a spokesman for an organisation with a key role in the recovery process said Sunday.

Paul Healy, of New South Wales Mine Rescue, said a giant jet engine shipped from Australia that is capable of blowing toxic gases out of the Pike River mine will allow rescuers to recover the bodies. The engine was being prepared for installation.

In his interview with Radio New Zealand, Healy also noted that time and care were needed to install the machine at the mine entrance and to establish the length of time rescuers could stay underground.

The best-case scenario is that it would be possible to recover the 29 bodies within the next few weeks, he said.

Grieving relatives, who were taken Saturday to the mine for the first time since the first gas explosion trapped the men underground on November 19, said being at the site had begun their process of healing.

But local mayor Tony Kokshoorn told reporters families would be in limbo until the bodies were recovered.

"You can't have closure until you're holding those bodies again, which is all part of the healing process," he said.

Since the initial blast there have been two further explosions at the mine and gas levels underground remain dangerously high, ruling out a quick recovery attempt.

Because of the danger, relatives, accompanied by Pike River chief executive Peter Whittall, were not allowed near the mine entrance when they were taken to the site in a convoy on nine buses Sunday.

They handed over flowers to company workers who promised to place them as close to the mouth of the mine as possible.