A man has been arrested on illegal firearms offences following an investigation and a search at Brukunga in the Adelaide Hills.

Just after 5.30pm on Friday 2 August, investigators from the Serious Firearms Branch and Eastern Adelaide detectives attended the property and conducted a search.

Police located a significant quantity of illicit firearms including handguns, semi-automatic rifles, a large quantity of insecure ammunition, a crossbow, silencer, a quantity of gun powder, reloading equipment, throwing knives, daggers, bayonets and a quantity of military ammunition.

Some of the firearms and ammunition were located in hidden rooms. Police also seized 32 registered firearms.

The occupant, a 53-year-old from Brukunga, was arrested and charged with firearm offences. He has been refused bail and will appear in the Adelaide Magistrates Court on Monday.