A grenade launcher, an M20 machinegun, a gas propelled anti-personnel mine and a "masterkey" 870 shotgun were among a cache of weapons found during the raid of a Newcastle home on Wednesday, police say.

Detectives allege Anthony Raymond Edwards, 49, of Charlestown illegally imported the firearms, firearm parts and ammunition from overseas.

Some of the items allegedly seized from a house at Charlestown in Newcastle. Credit:Australian Border Force

Mr Edwards is accused of importing the prohibited firearm parts and accessories between August 2016 and October 11 this year, but the vast majority of offences allegedly occurred during a five-week span, according to court documents.

Police allege that, during a short period of time, Mr Edwards bought weapons on 11 occasions from overseas and had been "active in his endeavours to import these items and conceal them from authorities", according to court documents.