New South Wales police have seized a cache of weapons including illegal guns, explosives and illicit drugs linked to the Hells Angels bikie gang.

Investigators will not reveal when the raid happened, but have confirmed two of the weapons seized are linked to previous crimes.

The Deputy Commissioner, Catherine Burn, says the haul was found in the boot of a car in a secure parking space in Sydney's CBD.

She says police found 10 sticks of Powergel explosives with detonators, four rifles, a shotgun, three pistols including a key ring pistol, three silencers, a large quantity of ammunition, 10 firearm magazines, various firearm parts, two stun guns, three kilograms of the illicit drug Nexus, night vision goggles, balaclavas and gloves.

"The fact that this car had explosives with detonators means that this is extremely dangerous," she said.

"People may have been killed. People may have been seriously injured. And substantial damage to property may have occurred."

Detective Superintendent Arthur Katsogiannis says it is crucial to reign in outlaw motorcycle gangs.

"They are violent organised criminals who will go to any length as these weapons displayed, to protect their business interests," he said.

The NSW Police Minister, Michael Gallacher says the Federal Government should do more to boost border protection.

"This was once the domain of the streets of LA and New York. Sadly this sort of weaponry is now on the streets of Australia," he said.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 4 minutes 3 seconds 4 m 3 s Guns and explosives found in suspected bikie hiding spot ( Brendan Trembath ) Download 1.9 MB

Police conducted a series of raids in March this year after a long-running investigation into the supply of drugs, guns and explosives to organised criminal groups.

Detectives from Strike Force Alistair arrested and charged 36 people who remain before the court on serious drug, firearm and other offences.

Police believe the vehicle was being used as a storage safe house by the Hells Angels.