The US-based Mongols are the self-proclaimed baddest bikie gang in the world.

A notorious international bikie gang involved in a recent North Island shooting appears to have expanded into the South Island.

Mongols MC members, including national president Jim Thacker, rode to Christchurch about 10 days ago when it is believed the gang patched up former members of the Hells Angels and established a chapter in the city.

The Mongols, whose patch depicts Genghis Khan on a motorcycle, was founded in the United States 50 years ago and describes itself as the "baddest and fastest growing club in the world".

SUPPLIED The Mongols, whose patch depicts Genghis Khan riding a motorcycle, are believed to have been involved in a gang shooting that left a Mongrel Mob-linked property riddled with bullet holes.

The first New Zealand chapter of the gang was set up in the Bay of Plenty last year, creating tension among rivals.

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Members are believed to have been involved in a shooting last week that left a Mongrel Mob-linked property in Tauranga riddled with bullets.

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The attack was thought to be in response to the arson of a Mongols-linked barber shop.

Thacker, 28, a former president of a Bandidos chapter in Queensland, is among hundreds of hardened criminals, known as 501s, deported to New Zealand since 2014 changes to Australian immigration law.

The arrival of the 501s, named after the character section their visas were cancelled under, has radically changed New Zealand's gang landscape.

STUFF In October last year, the Hells Angels moved out of their Maunsell St headquarters, which was later sold.

New groups, most notably the Comanchero MC and Mongols, have established and, according to police data, gang membership increased nearly 50 per cent in the four years to June last year.

At the end of August, the national gang register carried the names of 71 of the 501s.

Police previously said many of the deported gang members were powerful and influential figures in the Australian underworld who brought with them professionalism, a new flashy image and significant international connections.

There were concerns the arrival of the new international gangs – known for their propensity for violence, particularly their use of guns – would lead to clashes as rival groups like the Mongrel Mob tried to protect their turf.

The Mongols' recent trip to Christchurch wasn't without incident.

On January 23, police stopped seven patched members of the gang on the Kapiti Coast as they rode to the Cook Strait ferry terminal in Wellington.

Police had received complaints about the group's manner of driving, which included speeding and dangerous overtaking manoeuvres, Wellington district crime manager Detective Inspector Shane Cotter said.

Two of the bikies were forbidden drivers. They were arrested and had their Harley Davidson motorcycles seized. Others received warnings or infringement notices.

Cotter declined to comment further.

Stuff understands Thacker was among those who were stopped. His motorcycle, a white Harley Davidson, registration DPORT, was not one of those seized.

Several other people connected to the gang are believed to have travelled south in other vehicles.

Canterbury district organised crime manager Detective Senior Sergeant Joel Syme said he was aware of reports members of the Mongols had been seen in the South Island, but was "unable to comment on whether they've set up a chapter in Christchurch".

The Hells Angels' Christchurch-based branch, Quake City, recently disbanded.

The group moved out of its Maunsell St headquarters, which was later sold, in October last year.

In recent times, the Christchurch gang scene has been dominated by the King Cobras, Tribesmen and Mongrel Mob.

In 2017, police froze hundreds of thousands of dollars worth of assets belonging to the Head Hunters – then one of the major players in the city's underworld – including the gang's Sockburn headquarters.

Court proceedings in relation to that action is ongoing.