Police were called to the blaze at a property in Dukes Rd North about 12.15pm on Saturday.
Fire and Emergency New Zealand (Fenz) had requested police assistance due to ‘‘an arson at a shed’’, Senior Sergeant Anthony Bond, of Dunedin, said.
Officers arrived to find the man watching the fire. He lived in a campervan on the property and had allegedly lit the fire, Snr Sgt Bond said.
Police were also told he allegedly had ‘‘loaded firearms in his car’’.
A search produced a .22 hunting rifle, a .22 break-action pistol, a .303 hunting rifle and a total of 150 rounds of .22 ammunition.
The man did not have a firearms licence, Snr Sgt Bond said.
He was arrested and charged with lighting a fire in a prohibited or restricted fire season, under the Fenz Act 2017, and unlawful possession of firearms.
He was scheduled to appear in the Dunedin District Court on Thursday.
A Fenz spokesman said crews from Mosgiel, St Kilda, Lookout Point and Dunedin stations attended.
The small shed, about 3m by 6m in size, was ‘‘well ablaze’’ when they arrived.
