Pike River families say they don't know what will be found when the mine is re-entered which should be next month but some believe human remains could be in the main tunnel.
Twenty nine men died in a series of explosions at the West Coast mine on 19 November 2010.
No-one has been allowed up the mine tunnel since because of dangerous methane but the families have now been told the first re-entry should take place in mid June.
Solid Energy has confirmed that stages one to three of the tunnel re-entry plan have been completed and that includes putting a camera down through new boreholes, near a rockfall - around 2km into the mine.
It said the camera showed what was expected but it did not released any details.
Lawyer Colin Smith said they did not know what awaited mines rescue staff and there were parts of the drift which had not yet been viewed.
The next part of the tunnel re-entry involves plugging the tunnel, close to the rockfall, with what's known as rocsil - a resin which when mixed with a catalyst expands to as much as 35 times its original volume and hardens.
After that, inert nitrogen will be pumped in between the rocsil and the rockfall to displace the methane and the main tunnel will be ventilated with fresh air.
Meanwhile, singer-songwriter Dave Dobbyn performed a musical tribute to the 29 men killed there.
Dobbyn was commissioned to write a song for 'Dreams Lie Deeper', a Wellington concert tribute to mining communities throughout the world, but with a focus on Pike River.
Before a nearly-full house on Saturday night, the singer performed This Love backed by the Orpheus Choir, the Wellington Brass Band and the Wellington Young Voices group.
He said it was an honour to write and perform a Gospel song about hopefulness, love and loss.