The trial of former Pike River Coal chief executive Peter Whittall relating to the 2010 mining disaster that claimed 29 lives will be moved to Wellington.
Proceedings will be live streamed.
In a reserved judgment today, Judge Jane Farish noted there would be 113 witnesses in a complex and detailed case that was expected to take several months.
Given the complexity and length of the trial, she said she was satisfied it was in the interests of justice to transfer the proceedings. The public interest would be met by streaming the trial live on the internet.
Pike River families' spokesman Bernie Monk said he was "absolutely gutted'', noting the decision could not be appealed by the families because the case had been brought by the former Labour Department.
The ruling said there were 600,000 documents, one alone comprising 20,000 e-mails.
Mr Whittall was in charge of the mine at the time of the disaster that claimed 29 men's lives. He started as mine manager in 2005, and although he had shifted to Wellington by January 2010, he retained a shared office in Greymouth and travelled to the mine weekly.
One example of case law states that the courts have always required a strong reason for moving a trial from the original community concerned.
Mr Whittall's lawyer Stuart Grieve accepted there was significant community interest in hearing the case in Greymouth.
However, he said to an extent that had been served by the Royal Commission of Inquiry, and the court case against Valley Longwall Drilling and Pike River Coal Ltd.
He argued the defence would require facilities to be able to brief witnesses, and have access to adequate IT facilities.
There were limited flights from Christchurch to Hokitika, and overseas witnesses would have to come to Greymouth by way of Wellington or Christchurch.
The logistical challenges would be prejudicial to Mr Whittall's right to prepare and present his defence and his right to a fair trial.
Mr Grieve said Mr Whittall lived in Wellington with his wife and children, and helped "greatly'' running the family home.
When Mr Whittall had been in Greymouth since the mine disaster he had faced "significant animosity'', as had his legal team. If the hearing was in Greymouth, he would be put under "significant stress''.
Judge Farish said she had seen some of the hostility directed at Valley Longwall.
Crown prosecutor Brent Stanaway, representing the Department of Labour, argued that many of the families of the 29 dead generally resided in Greymouth. If they wanted to attend the trial in Wellington, it would be costly.
Mr Whittall's personal safety would be dealt with by the courts and adequate security could be put in place.
But Judge Farish ruled that the case was complex, the documents voluminous and the trial could last up to 16 weeks.
Responding today, Mr Monk said: "It has made us angry and more determined.''
With Mr Whittall prepared to summon so many witnesses, he said he could understand why the decision was made but that did not make it any easier to accept.
"From a logistical point of view I can understand the judge's decision. We've just got to live with it ... But it's not the same, watching it on the live feed.''
He described the situation as "an endless battle'' for the families of the dead men.
"All I want is accountability and I'm yet to see it.''
Some family members had indicated that they would make the trip so they could look the witnesses in the eye, Mr Monk said.
Mr Whittall faces 12 charges under the Health and Safety in Employment Act.
Both parties agreed they could not commence a defended hearing before January or February 2014.