Police say they are investigating new leads and re-examining forensic evidence from a Waikato murder 30 years ago.
Publican Chris Bush was shot dead just before midnight on Saturday, October 24, 1987, at the Red Fox Tavern in Maramarua.
Having closed up the tavern, Mr Bush was having a drink with three staff members when two heavily disguised men burst in yelling "This is a hold-up".
One man was carrying a double-barrelled shotgun, the other a baseball bat.
As Mr Bush stood up, he was shot and killed.
One of the men then ordered a female staff member to search Mr Bush's pockets for the key to the safe, which was cleared of cash.
The men tied up the three staff members before leaving.
Detective Inspector Gary Lendrum, who worked on the original inquiry, says police have received "credible information" that has reinvigorated the case.
"What it demonstrates to me is that there has been talk amongst a group of people as to who was responsible," he said.
"For whatever reason, they've kept that to themselves - whether that's misguided loyalty or whether it's fear."
The case featured on the Police Ten 7 television programme on Thursday night.
Det Insp Lendrum said he hoped people who know who was responsible would now have the courage to come forward.
"The men involved may have been intimidating 30 years ago, but they will now be middle-aged or older and you may now feel comfortable contacting police," he said.
With the advances in forensic science, Det Insp Lendrum said material collected at the time was being re-examined.