"I'm worried it will continue unless we do something about it. They must not be allowed to get away with it."
The minimum legal costs will be $30,500, Mr Ohlson says, but he fears they could double.
So, he has now launched a unique 'Project Red Zone' fundraiser on the PledgeMe website to try to cover the bill for him, and others, to go to court.
To encourage donations, he has vowed to personally respond to every big-hearted backer in an unusual way.
For a pledge of $5-plus, he will send the donor a hand-signed letter.
For a donation of more than $30, he will send out a personally signed picture postcard of himself, and for $100-plus, he will go on video-sharing website YouTube and thank them personally while holding a photograph of them.
For any generous backer who wants to pledge $1,000, the entertainer says he will write them a song and "personally sing it on You Tube with your picture in shot too."
Mr Ohlson, a pensioner, says he's aware of the financial risks in taking any legal action against the insurers, but he says "that risk is worthwhile taking".
"They're being allowed to get away with it. Now that's absolutely wrong," he said.
"There's a risk to that, because I've been a superannuitant for over three years, I can't afford to take things to the High Court. But that's what we're willing to do."
A victory in the High Court would set a legal precedent, he said, adding that the situation affected everyone in New Zealand because "earthquakes are not going to go away".