Body of father 'buried alive' in NT mine collapse may not be able to be recovered amid safety concerns

Mine experts are still developing a plan to recover the body of Craig Butler, who is presumed dead after he was buried alive in a huge wall collapse at an outback Northern Territory site.

It is not known how long it will take to reach the mining superintendent because the Bootu Creek open pit mine site is now too unstable and dangerous to enter.

At least 48,000 cubic metres of rock and soil is estimated to have trapped Mr Butler in the collapse on Saturday.

Mr Butler, a 59-year-old Darwin married father of two daughters, was caught at the bottom of the open pit mine when what the industry calls a "wall slip" occurred.

Operations have stopped in the open pit at the Bootu Creek manganese mine, located about 110km north of Tennant Creek, but processing has started again.

"Unfortunately, survivability for that person is very, very limited and it is likely he has died as consequence," police Acting Assistant Commissioner Travis Wurst told reporters.

"It is expected that it will take some time, maybe days, before we are able to put that plan in place and commence the excavation process."

The mine's owners OM Holdings safety record was questioned by Construction, Forestry, Maritime, Mining and Energy Union NT organiser Kane Lowth, who said employees told him there had been multiple wall slips at the site.

He accused NT WorkSafe of allowing OM Holdings to present it with its own reports on past incidents instead of investigating independently.

WorkSafe would not comment, citing the current investigation into last Saturday's accident.

In 2013, OM Holdings was fined $150,000 in the NT Local Court for causing a collapse that desecrated a sacred Aboriginal site at Bootu Creek known as "Two Women Sitting Down" in what was described as a landmark ruling.

Primary Industry and Resources Minister Paul Kirby refused to give details about past safety incidents at the site, which he said would be part of an investigation that the police are leading in conjunction with WorkSafe and the department.