A cache of high-powered weapons has been found in secret compartments in a Holden ute in Adelaide, with a 32-year-old man charged with firearms offences.
The find is also linked to the discovery of a clandestine methamphetamine drug lab in NSW where two people were arrested in January.
Police described the concealed compartments, behind the driver and passenger seats, as professionally fabricated.
The cache included a Steyr 5.56 fully automatic military rifle, which is now subject to an Australian Defence Force investigation.
A Colt rifle and scope, a Glock handgun, a Luger handgun, a Ruger revolver and ammunition were also seized.
Detective Superintendent Stephen Taylor said the seizures were significant and revealed the breadth of the offending that serious organised crime syndicates were involved in.
"Law enforcement agencies across the country are sharply focused on disabling and dismantling serious organised crime syndicates who think they can operate their illegal activities with impunity," he said.
"These criminal syndicates need to know that we will be relentless in our investigations of their insidious activities at all levels, and take every opportunity to impact their business."
The arrested man was refused police bail to appear in Adelaide Magistrates Court on Friday.