Police will not enter the Pike River mine before the drift is fully recovered unless critical evidence is found.
More details about their role in the re-entry emerged on Thursday.
Police have decided the safest option is to wait until the drift is fully recovered, before considering deploying staff.
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But in the event of a 'critical find' being made, police may consider deploying staff into the drift before it is fully recovered, provided it is safe.
Assistant Commissioner of Response and Operations Tusha Penny says this approach is the safest way forward and consistent with the best practice of forensic scene examination.
"Once the drift is fully recovered we will have a much better understanding of the environment inside the mine, and be in the best position to make informed decisions about our own staff entering the drift."
Should a 'critical find' be made, police will consult with the Pike River Recovery Agency (PRRA) and independent experts to assess and understand the stability of the mine and the relevant underground emergency management measures.
If police staff are not deployed early in the event of a 'critical find', then underground PRRA staff will be briefed and supported by police specialists above ground to gather any essential forensic evidence required.
It's been eight years since the Pike River tragedy where 29 men lost their lives, and what really happened is still being uncovered.
In December last year, the Government delayed the re-entry until the end February.