The Pike River saga is back in court today, with legal action being taken over the decision to drop all charges against former mine boss Peter Whittall.

Twenty nine men lost their lives in the 2010 disaster.

Pike River boss Peter Whittall initially faced 12 charges related to failing to ensure the safety of workers in the mine, but these were dropped in December 2013.

That same day, Mr Whittall and the Pike River directors offered a voluntary reparation payment of $110,000 to the families of each of the men killed in the blast, as well as the two survivors.

A Judicial Review into the Crown's decision to drop the charges is being held today in Wellington.

Sonya Rockhouse, who lost her son Ben in the explosion, and Anna Osborne, who lost her husband Milton, have taken the legal action.

The women are arguing the Ministry of Business, Innovation and Employment's failure to put up evidence, and for the court to hear evidence, was unlawful and invalid.

Bernie Monk, long time spokesman for the families, will be at the High Court today with his wife Kath.

They lost their son Michael in the blast.

Newstalk ZB reported a small crowd of family and supporters had gathered outside the court this morning.

The hearing is expected to run for two days.

Nigel Hampton, QC is representing Ms Osborne and Ms Rockhouse, while Joanna Holden is representing Worksafe.