Five people have been arrested and hundreds and thousands of dollars in assets seized in a drug bust in Wellington.

Photo: Supplied/ police

Yesterday police arrested four men and one woman, after a long-running investigation into the importation and sale of the Class C drug N-Ethylpentylone.

The operation began in November last year.

Police seized over $405,000 cash, about 6kg of the drug, and seven vehicles including two Harley Davidsons, an Audi, a Mercedes, and a Maserati.

They also took $200,000 of Bitcoin and other cryptocurrencies.

Two of the men arrested have been charged with a range of drug-related offences, and will appear in the Wellington District Court today.

The other three were due to appear in court on Monday.

Anyone dealing drugs could expect to be a target of similar operations Wellington acting detective senior sergeant Shane Dye said.

"If you are a drug dealer of any kind, we will come after you, we will hold you to account and we will restrain and obtain forfeiture of your assets.

"We hear a lot about the harmful impact of Class A drugs like methamphetamine, but this drug - and others like it - are also doing real harm."