One of two cousins facing firearm charges following an armed police operation has pleaded guilty to possessing a 12 gauge single action shotgun.

Damien Maney, 34, admitted the charge when appearing in Tauranga District Court this week but denied possessing cartridges and a sawn-off shotgun.

Armed police searched a vehicle on Willow Street on August 30, 2013.

Maney is jointly charged with his cousin, Jason Rex Thomas Maney, 33, who appeared alongside Damien on Thursday.

Jason is also charged with being in possession of an explosive – one round of shotgun ammunition.

The pair were arrested on August 30, 2013, when armed police stopped and searched the vehicle the cousins were travelling in during a routine vehicle stop in Willow Street.

Police allege two firearms and ammunition were found in the car the cousins were in.

During Thursday's trial callover date, Jason's lawyer John Holmes said his client was maintaining his not guilty pleas on all charges because he was not the driver of car.

'He was not the owner of the vehicle and the only thing linking him to the incidents is a text message.

'He didn't have anything to do with what happened on that day.”

Jason Maney is currently serving a six-month jail sentence for his first driving while disqualified offence.

He is also disqualified from driving for 12 months from February 22, 2014, once his jail sentence is complete.

Judge Thomas Ingram remanded Jason in custody until February 20, while Damien was remanded on bail until the same date.