The families of the men who died in the Pike River coal mine say the owner of the road accessing the mine has given control of it to them.

The families of the 29 men who died in the mine in November 2010 have been fighting the sealing of the mine, saying the drift, a tunnel leading to the mine proper, is safe to enter.

The mine was privately owned at the time of the explosions but is now owned by state-owner coal miner Solid Energy, which said the mine is not safe to enter.

The families have been protesting on the road to the mine, and on Sunday posted on social media "there's been a wee development".

"Turns out, Solid Energy don't own a big slice of the road to the Pike River access road, and don't have any legal right to access it."

It's the only way to get to the mine in the West Coast region of New Zealand's South Island.

"Oh, and the lovely local farmer who does own it, being a top bloke and loyal Coaster, has given control to us.

"So, you know, we'll try hard to be reasonable landlords. We'll allow access for genuine emergencies, if they ask nicely. But, well, that'll be it for now.

"The town bully just went down."

The Pike River families plan to go to parliament in Wellington on Tuesday to present the new prime minister with a new legal and technical plan to allow for re-entry of the drift "to retrieve evidence of what happened to our boys, and any remains which may lie there".

Last week, Solid Energy published an open letter in newspapers explaining its position.

It rejected claims a "quick" inspection of the 2.3km drift, or entry shaft, is safe, that it is not listening to families' experts, talking to the families and acting with indecent haste.

It also labelled the idea the mine was being sealed because it had something to hide or was colluding with the government in a cover-up plot as "incorrect and farcical".