Insignia at the Christchurch headquarters of the Comancheros motorcycle gang is no longer being brandished.
The removal comes after police confirmed it had arrested every member of the gang's Christchurch chapter in a major drug bust last week.
Capping an eight-month investigation dubbed Operation Avon, 5kg of Class A drugs, 11 firearms, ammunition and about $250,000 in cash were seized after about 70 warrants were executed in Christchurch and Auckland last Wednesday.
Eleven vehicles and an Auckland property, worth a combined $1.9 million, were also seized.
Although it is unclear when the signage was removed, when RNZ visited the Christchurch headquarters on Thursday, the gang's emblem was no longer displayed on the front of the building.
Police have been approached for comment.
Eighteen men, aged between 18 and 55, were arrested, later appearing in court in Christchurch and Auckland.
Twelve of the group were in Christchurch with the remaining six appearing in Auckland.
Charges included participating in an organised criminal group, conspiracy to supply methamphetamine, and conspiracy to supply cocaine. Further charges of money laundering and drug dealing were being considered.
Police said the drug offending involved methamphetamine and cocaine.
"These groups have no hesitation in peddling drugs and accumulating vehicles and property, with no regard for the destruction they cause in everyday New Zealanders' lives.
"We have no doubt that this disruption of the Comanchero gang will have a positive impact on the drug supply chain across the country."
Police alleged the Comancheros organised for drugs and cash to be relayed between Auckland and Christchurch every few weeks.
Detective Inspector Darrin Thomson said police believed $15 million worth of drugs were moved between the North and South Island.
"Our investigation showed that they were bringing from the North Island down to South four kilos a fortnight, and to give you some idea that's $1.4 million street value every fortnight," Thomson said.
"The prosecution will allege this groups is responsible for supplying more than 60 kilos of Class A drugs during the investigation phase... that's over two million doses of those Class A drugs into our community and that's just horrific.
"Operation Avon is holding those responsible to account following a meticulous investigation and coordinated response.
"Pivotally, arresting every member of the chapter will put an end to their unwanted presence in our Christchurch community."
The Comancheros was founded in Scotland by a biker called William George "Jock" Ross, who named it after a 1961 John Wayne Western movie and brought it to Sydney when he emigrated in 1968.
From its early days importing amphetamines, the gang were soon involved in cocaine smuggling with links to Middle Eastern organised crime gangs in South-east Sydney.
In recent years, the gang has been associated with a string of brawls, skirmishes and assassinations in the Sydney underworld, which has seen 18 people killed - some in broad daylight.
