Thousands of rounds of ammunition and several firearms have been seized and a substantial cannabis grow room discovered in rural Blenheim, police say.
The room was found following a routine rental property check at an address on Tuesday.
The firearms seized included a loaded .22 calibre pistol, a loaded cut-down shotgun and a semi-automatic MSSA (AK47 type) with loaded magazines, police say.
Body armour and camouflage gear were also found.
A 50-year-old man, who does not hold a firearms licence, has been arrested and is due to appear in the Blenheim District Court on Monday, police say.