Investigators have suspects in the firing line

Prosecution cases are now being pieced together regarding several of the fires. Photo / Supplied

Fire investigators believe they know some of the people responsible for 49 Wairarapa wildfires in the past five weeks.

The fires have threatened millions of dollars worth of farms, homes and forestry.

Phill Wishnowsky, Wairarapa principal rural fire officer, said three of the larger blazes had each cost the rural fire service alone more than $30,000 to battle, without including expenses for the paid, private and volunteer crews.

He said prosecution cases were now being pieced together regarding several of the fires and charges would soon be laid linked to a runaway blaze last weekend at Mangatoetoe, near Ngawi, on the South Wairarapa coast.

That fire forced the evacuation of several of the two dozen homes at the location, with one resident left hospitalised "who had been overcome by heat and exhaustion after desperate attempts to save their house".

Wishnowsky said though there was no singular pattern to the blazes, most were found to have been caused through deliberate breaches of the restricted fire season and "sheer stupidity".

He said the restricted fire season began in Wairarapa on December 17 and breaches, if successfully prosecuted, made culprits liable for damage and firefighting costs, as well as a maximum fine of $1500 or two months' imprisonment.

"That's a huge number of fires that I believe is a record.

"But whether it's a record or not is irrelevant. Most should never have happened," Wishnowsky said.