A man has been buried under "a significant volume of soil and rock" when a wall collapsed at a manganese mine in the central Northern Territory.

Key points: A 59-year-old Darwin man is missing after a mine wall collapsed at Bootu Creek managanese mine

A 59-year-old Darwin man is missing after a mine wall collapsed at Bootu Creek managanese mine Alice Springs and Tennant Creek investigators are at the site

Alice Springs and Tennant Creek investigators are at the site The Bootu Creek mine is owned by Singapore-based OM Holdings and was placed in administration in January 2016, before resuming operations in early 2017

NT Police said that at 2:40pm on Saturday "there was a substantial wall failure on the Western Limb" at the Bootu Creek Mine site, about 110 kilometres north of Tennant Creek.

"An employee is believed to have been engulfed under a significant volume of soil and rock," police said in a statement.

The 59-year-old man is from Darwin, police confirmed.

NT Police Superintendent Chris Board said the man's chances of survival were low and excavation to look for him had been delayed.

"Sadly, due to the nature of the collapse, the information thus far indicates that the likelihood of survival is low," he said.

"The instability of the site remains very real, which has delayed any excavation of the site at this time.

"Experts are arriving at the scene and they will provide expert advice and opinion in relation to the stability."

NT WorkSafe have been notified about the incident and investigators have been on site.

The mine, located north of Tennant Creek, is owned by Singapore-based OM Holdings. ( Matt Brann )

Superintendent Board said he could not speculate about whether charges would be laid.

"We're only 24 hours in," he said.

He said a joint investigative team had been set up with representatives from the Department of Primary Industry and Resources.

An OM Manganese employee in the mine site office declined to offer any comment and referred queries to the NT Police.

The ABC was asked to leave the site, after filming at a locked gate being guarded by two employees.

The Bootu Creek mine is owned by Singapore-based OM Holdings and was placed in administration in January 2016, before resuming operations in early 2017.

About 140 workers lost their jobs when the mine was mothballed, largely due to a drop in ore prices, and only returned to full production in 2018.

The open-cut mine trucks its ore on a specially built road to the Adelaide-Darwin railway line 60 kilometres away for transport to Darwin, and then onto ships bound for overseas markets.

The 2018 annual report of OM Holdings said the mine produced 814,040 tonnes of manganese ore in the year.