Families who lost loved ones in Christchurch's CTV building collapse are planning to fight harder than ever to get justice after meeting with police.

Professor Maan Alkaisi, who lost his wife in the collapse, is not convinced by the arguments put up by the police and the solicitor general.

"(After the meeting) I am now determined to go ahead and keep fighting until justice is done," he told media.

Police announced they would not be prosecuting the engineers of the CTV building earlier this month.

The building collapsed after the 2011 February earthquake, killing 115 people including 65 foreign students.

A meeting on Thursday gave families the chance to ask the experts questions about why a three-year-long, $1.18 million criminal investigation led to no charges being laid.

Police said legal advice suggested they were unlikely to get convictions if charges were laid, despite a 2014 engineer's report identifying a number of defects in the building's design.

"After listening to other families it was clear that the police arguments were not convincing," Prof Alkaisi said.

Detective Superintendent Peter Read told media it was a productive meeting and good for the families to hear the decision process.

But when asked if a judicial review of the decision not to prosecute would go ahead, he said that would be up to the families.

The families will also meet with Minister of Justice Andrew Little on Sunday.

Det Supt Read will fly to Tokyo next week to meet with families of the students.