Criminals are taking advantage of residents' trusting nature, police say.
Between August 9 and September 9, there were 31 reported burglaries in Oamaru.
Of the 31 burglaries, 11 were of garages - all of which had been left unlocked.
Sergeant Tony Woodbridge issued a warning to Oamaru residents to lock it, or lose it.
''Oamaru people are very, very trusting - probably the way New Zealand used to be and the rest of New Zealand would like to be, but we've got to be careful because there are dishonest criminals out there that will take advantage of our good nature,'' Sgt Woodbridge said.
Tools appeared to be the most sought-after items.
