The Headhunters gang is making millions out of its crime network and, according to the police, is now one of the most feared criminal organisations in the country.

It allegedly protects and extends its interests through murders, disappearances and extortion as well as dealing in and manufacturing drugs.

The West Auckland motorcycle gang has become so powerful it is feared even by other serious criminal elements.

"The Headhunter Motorcycle Club is considered one of the most dangerous organised criminal operations in the country. It controls the West Auckland crime scene," a former undercover officer, Detective Sergeant Craig Martin Turley, said in a rare lifting of the veil on the shadowy criminal underworld.

"They are responsible for the manufacture, sale and distribution of Class A, B and C controlled substances, with deals taking place throughout the country.

"The organised theft, receiving and distribution of stolen property has a value, over the years, in the millions.

"The murders, serious assaults and suspicious disappearances are also cause for considerable alarm. The extortions, home invasions and robberies are ongoing."

Detective Sergeant Turley was involved in a large number of covert drug and serious crime operations between 1993 and 1996, infiltrating the drug scene while targeting organised criminal operations and gang activity.

His outline of gang activity was given this week to the Liquor Licensing Authority when police opposed renewal of licences of a Helensville tavern alleged to be associated with the gang's president, David Smith.

The Headhunters gang was formed in Glen Innes in 1967, moving to West Auckland in 1978, becoming a motorcycle club about 1985 and an incorporated society in 1996.

"It quickly established a reputation for violence - a reputation respected by other gangs," said Detective Sergeant Turley.

As its reputation grew, it restricted numbers and, in its own eyes, became an elite group. It has fewer than 30 patched members.

"Without doubt, the Headhunter motorcycle gang are an established, organised criminal enterprise of the highest order," said Detective Sergeant Turley.

"Their being a tight-knit group with good internal security makes infiltration and general targeting of the group difficult."

The gang had sophisticated security measures, including guards, at its Henderson headquarters.

It swept for listening devices and used counter-surveillance methods.

On top of that, said Detective Sergeant Turley, it used obstructive behaviour and legal measures to counter police investigations.

"Despite their internal security and active anti-law-enforcement measures, Smith's gang has amassed in excess of 1000 convictions. They are known to have committed and are currently under investigation for the most serious criminal offences."

It was clear Mr Smith and the gang were committing alcohol, drugs and lotteries offences at the headquarters.

That was confirmed during raids in November and December, which will result in a court case next month involving alcohol and gaming charges.

(A member of the authority, Jim Thompson, asked why it had taken so long to clamp down on the gang. Detective Sergeant Turley said: "Organised crime, until late, has been investigated piecemeal. It has evolved at such speed it has caught us by surprise.")

Functions at the headquarters, especially "dance and rave" parties, were an outlet for the sale of illegal substances, the detective said.

"Although the sale of alcohol is profitable at such functions, the sale of Ecstasy and methamphetamine is the major source of income."

Detective Sergeant Turley said "outlaw motorcycle gangs" were recognised internationally as major players in drug distribution and other offending.

Legitimate businesses were often purchased as an effective cover for drug and extortion work. "They are also extremely useful for the laundering of 'dirty money.' Common businesses are debt-collection agencies and security-type businesses."