The police's Financial Crime Group led a year-long investigation, called Operation Martinez, focusing on money laundering and related offending.
The group's national manager, Detective Superintendent Iain Chapman, says the figures involved are "eye-watering".
"Our investigation has discovered that this group of individuals have dealt with transactions in excess of $120 million.
"While it's possible some of these funds are legitimate, as a result of months of investigation police suspect a significant amount of these funds dealt with were illegally gained through criminal offending.
"The investigation team will now work to reconstruct the activities of the business to determine the source of these funds and our inquiries are ongoing in this area."
Police earlier asked anyone who knew the whereabouts of the Rolls Royce to contact them on 105.
Eight properties in total have been seized in central Auckland, Albany, and Glenfield.
Those arrested are six men and one woman aged between 29 and 48 years. They are not known to be linked to any of the 501-deportee gangs.
One person is also facing charges relating to the supply of methamphetamine after a quantity of the drug was located at one of the properties.
It's alleged those involved have laundered millions of dollars through the company, which has been running since 2017.
Police say those involved knew it had been gained through criminal offending such as drug dealing, fraud, theft, and burglary.
Chapman says the syndicate posed as a legitimate financial service provider, with offices around Auckland city.
"It's been a year-long covert investigation by members of the financial crime unit by members up and down New Zealand but by no means is it over," he says.
"We are now going to spend the next weeks, the next months, poring over the books or lack thereof within these businesses to try and truly establish the level of criminality."
The group is expected to appear in the Auckland District Court tomorrow.
Last month, police arrested six people and seized millions in assets after early morning raids in Auckland.
Seven high-end luxury vehicles, a boat and three motorbikes - with a combined value of more than $1.2 million - were seized by police.
The luxury vehicles include a $450,000 Lamborghini Huracan and three new 2020 Mercedes-Benz models, including a $280,000 G-wagon, police said.
Three properties in Half Moon Bay, Te Atatū and New Lynn - worth at least $3.3m - were restrained and about $250,000 in cash was also seized.
The arrests are the result of Operation Brookings, a long-running investigation by the Financial Crime Group.
Op Brookings and Op Martinez are not linked directly, Chapman says.
"We saw, as we do with any business, crossovers but this is a separate syndicate," he says.
"The difference between Operation Brookings and this one was that this was a business portraying itself as a legitimate company."
