A Perth man charged with 15 firearm-related offences after a remote WA traffic stop last year will vigorously defend the matter at trial, his lawyer says, as new information about the case comes to light.

WA defence lawyer Ross Williamson says his client, a 39-year-old man, will strongly defend the 15 charges, and was licensed to possess the guns subject to the alleged offences.

Shark Bay police tweeted this picture of the guns back in October. Credit:Shark Bay police

WAtoday understands the man was carrying out work for a WA government department when he was stopped on the remote North West Coastal Highway on October 6.

It is understood he had been on his way to a nearby rifle range to test the firearms for that government department.