Watch: Massive tyre fire in Dunedin

Fire investigators are looking into the suspicious circumstances of a large blaze in Dunedin overnight.

Firefighters were called to what was initially reported as a fire in a wood shed at a property on Kaikorai Valley Road, in Burnside, just after 12.30am.

The site is at The Woodshed, said to be Dunedin's largest undercover firewood supplier.

Southern fire communications shift manager, Andrew Norris, said: "When they got there, they reported that there was actually a large amount of tyres on fire. They had to use foam to try and extinguish it.

"We ended up with four fire engines there and they were there for most of the night."

One crew remained at the site early this morning, just after 7am.

Mr Norris said at this stage, the Fire Service was treating the blaze as suspicious and would be carrying out the necessary investigations.

At the scene early this morning, Dunedin senior station officer, Stephen Clarke, said they used a digger from a local company to help them get to the heart of the blaze.

Mr Clarke acknowledged the suspicious circumstances, saying: "Tyres are very difficult to go on fire...they are very difficult to put out and require a lot of water.

"It's very difficult to determine the cause. Historically, tyre fires have been deliberately lit. Unless we get good information as to persons unknown who may have been in the area, it will probably remain as undetermined.''

No buildings were damaged in the blaze and no one was injured.

A large cloud of smoke hovered over the area for some hours, as crews worked to douse the blaze.

Asked if the fumes were potentially dangerous, Mr Norris said they did not believe so and the fact that the fire happened quite late at night, when people were inside, had helped keep people away from the area.