They fear it is already in international waters. If it was still in New Zealand someone would have recognised its distinctive, one-off design by now.
Senior Constable Peter Comer, coastal master at the Auckland Police Marine Rescue Centre, said the link between the fugitive couple and the missing yacht was so far only speculation.
However, it was one of the possibilities police were looking into. Customs has been alerted as had authorities in likely destinations in Australia and around the Pacific.
Police had received a report of a possible sighting at Whangarei Harbour's Woolshed Bay a few days ago. He did not believe it was the missing yacht but not yet been able to rule it out.
Meanwhile, police were examining every option, Mr Comer said. "We're not saying it's left the country, it could be hiding around the coast somewhere. Unfortunately, once a boat leaves our shores undetected, it's very hard to track. The chances of recovery are very low."
He urged anyone who had seen the boat, or knew where it was, to contact their local police station.
"It's a $150,000 boat. We'd love to find it," he said.
Mr Jacomb, a director of Canterbury helicopter firm HeliPower, alleged the couple had cheated the company of $250,000. He had put up the bounty in the hope it would lead to their capture.
The Hollands had sailed Harlech to the Pacific Islands and around Northland many times, living on board for six months at a time.
The fibreglassed kauri cutter had many personal items on board, including a log book recording their Pacific voyages.
Northland Regional Council deputy harbour master Chidambaram Surendran said thefts of ocean-going yachts were unusual. An alert had been sent to harbour and coastal wardens; the country's sailing fraternity is also keeping an eye out for the missing yacht.
The last confirmed sighting of Bennett was in Nelson last June.
- additional reporting NZME.