Luxury Queenstown properties, cars, cash and a boat are among assets worth almost $2 million seized by police as part of a drug ring raid in Southland and Otago.

The ring had been operating for at least 20 years, growing cannabis in bush fringes and remote areas of western Southland, police said earlier.

On Thursday last week police raided a number of properties where they arrested five people "from all walks of life" and brought in about $1m worth of dope.

On Monday police released a statement saying $1.8m worth of assets had been seized at the weekend.

This included two Queenstown Lakes properties worth a combined $1.2m, an Invercargill property worth $380,000, about $100,000 in cash, a $38,000 boat and two cars worth a combined $45,000.

Three Queenstown men, aged 62, 55 and 50, appeared in Queenstown District Court on Monday and two Invercargill men, aged 42 and 33, appeared in Invercargill District Court last Friday in relation to the bust dubbed "Operation Canary".

A Dunedin man in his late 40s was arrested earlier this year.

All have been charged with cannabis offences.

Two further arrests are likely.

In 2008, Winton police began investigating drug growing and dealing in the area, and the investigation spread to Fiordland and Queenstown Lakes.

It pointed them to a growing syndicate, involving millions of dollars, operated by people from Invercargill and Queenstown.

During the 2011/12 cannabis growing season police found about 41kg of high-quality cannabis, with an estimated street value of around $1m.