The blaze led to nearby homes being evacuated and extensive damage to the property.
The 48-year-old man was arrested and charged with intentionally damaging an empty Lees St, Dunedin, home on Tuesday.
According to the court charge sheet, he lit the fire by throwing Molotov cocktails through a window.
Neighbours were woken early in the morning to find a huge blaze in the house. Nearby residents were evacuated for several hours as firefighters fought the blaze.
The alleged arsonist was arrested and charged on Wednesday, Senior Sergeant Anthony Bond, of Dunedin, said.
Detective Senior Sergeant Nik Leigh this morning thanked the community for information provided so far.
“The arrest is a significant development for us; the investigation team has been chasing down a lot of leads but there’s still work for us to do.
“We’re grateful for those people who have provided information, but we still need to hear from anyone with information who has yet to reach out.
"If you have any details that could help our enquiries, please contact us."
The Lees St blaze was one of three suspicious fires in Dunedin over several hours starting late on Monday night.
The first blaze at 11.30pm severely damaged a vacant commercial building in Harrow St. About an hour later, police were called to the Lees St fire.
A Fire and Emergency New Zealand (Fenz) spokesperson said that blaze reached second-alarm status, and half a dozen appliances were deployed.
The spokesperson said Fenz was initially concerned the house was occupied, but that turned out not to be the case.
An hour later, emergency services were alerted to a fire in a stand of trees outside the Otago Pistol Club in Waldronville.
Five trucks, two tankers and two rural crews were sent to the scene and, when crews arrived, the flames were about 20m high.
Police said a stack of newspapers was located near the scene.
This fire was also believed to be intentionally lit.
A Fenz spokesperson said investigators were looking into the cause of the fires.
Det Snr Sgt Leigh said nobody was injured, but that didn’t make the fires any less serious.
“Fire spreads incredibly quickly and it puts everyone at risk, from the public to emergency services.
"We treat these events seriously, and the arrest we’ve made in this case is a welcome development.”
He urged anyone with information to contact police online at police.govt.nz, clicking update report, or by calling 105, using the reference number 251118/1721.
Information can also be provided anonymously via Crime Stoppers on 0800 555 111.
