UPDATED 3:02pm: Crime doesn't pay, if police and Customs have their way.

Police are trumpeting another big drug bust.

They believe they've broken the supply line into Wellington responsible for a worrying new trend.

Three men and a woman have been charged and over the importation and supply of a drug known on the streets as "Niff” or "Bath salts".

The substance is only rated as a Class C drug but police say it has a similar effect to powerful psychoactive agents.

Assets worth about a million dollars have been confiscated including two houses, cars, boats, a jet ski, and a stash of bonus bonds.

More than $100,000 worth of bonus bonds has also been seized.

Detective Senior Sergeant Brent Murray warns the police will not tolerate drug manufacturing and dealing.

"If you want to get involved in this type of offending, police and customs will continue to target those involved and make sure that crime does not pay."

The bath salts bust is not related to yesterday's mammoth methamphetamine sting in Auckland.