Securing a conviction against those involved in building and designing the CTV building is unlikely, legal experts say.

Police have said they will investigate the findings of the Canterbury earthquakes royal commission on the disaster, released on Monday, and consider laying charges.

Some survivors and families of the 115 people killed in the tragedy called for prosecutions and compensation after it was found the building had design and construction flaws that contributed to its collapse, and should not have been issued a building permit.

Christchurch lawyer Nigel Hampton, QC, said pinning those faults to individuals would be difficult.

"If you're talking manslaughter . . . you'd have to show gross negligence.

"You'd have to choose your individuals with some care. You'd have to show gross negligence on their part and be able to prove that beyond reasonable doubt.

"You've got to show that . . . was an actual cause of the collapse of the building causing death."

Auckland University law professor Bill Hodge said it would be a tough case to pursue, but that may not be an issue for the police.

"[The police] know the public feeling and the depth of feeling. . . [they] may feel it's their role to provide a day in court for those people [and let] the courts decide."

Hodge believed police attention would likely focus on Alan Reay as principal of the company that designed the CTV building. "We're talking about the most serious stuff in the book. I guarantee somebody is looking at [it] right now."

Reay in July told the royal commission his firm was "ultimately responsible" if design flaws were found to be the reason for the collapse.

David Harding, the man who designed the CTV building and who commissioners found was unknowingly out of his depth, would warrant less attention, Hodge said. "If he didn't know that he should have known then it's not sufficiently serious to get him into that ballpark."

Lesser charges could include criminal nuisance, he said.

The other possible target was the Christchurch City Council, but both men agreed any action would be difficult with no corporate manslaughter charge in New Zealand.

Civil action would be equally hard.

The criteria and process to win such a case was rigorous, Hodge said, and families and survivors should "think very, very carefully" before pursuing it.

Hampton said: "I think they've got some problems.

"You've really got to show a gross malfeasance in the execution of a public duty and that's a pretty high standard."

Reay declined to comment on the findings or the police investigation. He had still not received a hard copy of the report, and it would be some time before he could comment on it.

Harding's lawyer, Michael Kirkland, said it was too early for his client to comment.

- © Fairfax NZ News