The security guard was described by court staff as "being liked by everyone".
There was no Automated External Defibrillator (AED) at the court despite lobbying from unions - and it's an absence that could have directly contributed to his death, experts say.
Green Lane Cardiovascular Research Unit director Dr Harvey White said it was a "travesty" there was no defibrillator at the court and it should be a wake-up call. He has been advocating for years about the importance of installing the device, particularly at places large numbers of people visit.
There were now 4000 defibrillators nationwide - but he said there should be at least 10,000.
Running across the road for a defibrillator wasted precious minutes and every minute delay meant a 10 per cent increase in mortality, he said.
Heart Saver NZ managing director Mike Mander said it was irresponsible the Government did not have the basic first aid tool onsite.
"[The Government] should be leading by example, not waiting."
At least two other people have died as a result of heart attacks in New Zealand courts but there was no media coverage of the events, he said.
Public Service Association spokesman Basil Prestidge said the organisation had been lobbying the Government to put in defibrillators at all New Zealand courts for a long time.
There were also suggestions the security guards lacked sufficient training for the job and did not wear stab-proof vests, he said.
Ministry of Justice property manager Fraser Gibbs said the ministry was "working through an all-of-Government procurement process" to purchase defibrillators for all courts.
"We looked at several options before settling on a contract that we are in the final stages of working out. Obviously, we are very sad at the death of a familiar face at the courthouse and are supporting our staff though this."
There would be two defibrillators stationed at the Auckland District Court once the process was complete, he said.
Christchurch and Kaikohe district courts and high courts in Auckland and Wellington have defibrillators, which were donated by St John.
Detective Sergeant Nick Poland said the security guard had been carrying out routine duties in the cell block before a possible heart attack.
Mr Poland said staff at the court were devastated about the loss of a colleague who was "liked by everyone".
Defibrillator stats
• A defibrillator is a portable device that delivers an electric shock through the chest to the heart.
• People who suffer a heart attack have a survival rate of about 2-7 per cent if there is no defibrillator present.
• Every minute after the heart attack without a defibrillator increases the chance of death by 10 per cent.
• The devices are sold for about $2000 each.