Pike River Coal's chief executive broke down in tears at an inquiry into the mine disaster on Friday, admitting he could have handled the situation better with families but says information was kept from him.
Peter Whittall appeared at the Royal Commission being held in Greymouth into the deaths of 29 men in a series of explosions that began at the West Coast mine on 19 November last year.
The second phase of the inquiry looking at the search and rescue response concluded on Friday.
Mr Whittall told the hearing about his communication with the families regarding the operation and was in tears several times during his evidence.
The chief executive has come in for extensive criticism from some relatives of those who died - in particular for the way the meeting where they heard of the second explosion was handled.
At first, relatives were told that the gas levels had improved and that the Mines Rescue Service had been preparing to enter the mine. Family members burst into applause, only to then be told that there had been a second explosion on 24 November and there was no chance of anyone surviving.
Mr Whittall told the hearing he was surprised when the families became so excited at news that Mines Rescue had been been preparing for a re-entry, as he thought he had made it clear it was in the past tense.
He said there were thousands of better ways he could have conveyed the news and has regretted it ever since.
Mr Whittall said it had been "gutting" to hear that the families felt he had let them down, and had raised false hopes and kept information from them.
"I didn't know what I didn't know'
Peter Whittall said that it had become clear through the inquiry that he did not have all the information needed to keep the families up-to-date and was disappointed that things had been kept from him.
Mr Whittall says he tried to get as much information as possible every day by speaking to the senior police in charge of the response and the incident controller on site.
He says it is now clear he was not told information which those people had and deeply regrets that.
"Every day I availed myself to the best of my ability of information by directly speaking with the police superintendent, meeting with the Police Commisioner, meeting with everyone I could.
"And yet, I still was not told information that was evident to those people. I didn't know what I didn't know ... I deeply regret that."
Mr Whittall says despite people now giving evidence saying it was clear that the men had died after the first explosion, none of them had said that to him.
Questioned earlier in the hearing about information he gave the men's families after the initial explosion on 19 November, Mr Whittall said he genuinely believed some could have survived that blast and is absolutely sorry if he made the situation worse for families by sharing that hope.
Mr Whittall said he knew what the men were capable of and held on to the hope that at least some had survived.
The Royal Commission hearing will resume in November.