Each volunteer with the Vigili del Fuoco (Firefighter Corps) was paid about 10 euros (US$11.70) per hour.
The commander of the team, Davide De Vita, 42, who has been placed under house arrest, is accused of skipping shifts in order to start the fires.
#Vigilidelfuoco #Canadair CL-415 Italian Fire Hunter scooping water from #LagoAlbano near #Castelgandolfo. pic.twitter.com/HtWu2EDgFi
— bcd (@bdosier) August 3, 2017
There have been numerous fires in France and Italy this year, so the blazes in the Ragusa district of Sicily did not initially raise any suspicions.
But the island's Squadra Mobile police force, led by Captain Antonino Ciavola, eventually realized the Ragusa squad, based at Santa Croce Camerina, was dealing with considerably more blazes than other crews.
all the woods near Messina, Palermo, Trapani and the airport of Catania are burning. Sicily is a fire. pic.twitter.com/pVKgqQMm7v
— Nιαll ιs hømε🦋-239ℋ (@iwantneil_) July 12, 2017
There have been 120 call-outs in Ragusa this summer, compared to 40 each in the equally hot summers of 2013 and 2014.
The volunteers would start the fires and then either call them in themselves on the 115 number used across Italy for fire emergencies, or they would persuade a friend or relative to make the call.
Then they would wait to be called to put out the fire, often taking as long as possible to ensure maximum payment.
Mr. De Vita allegedly lit fires even after he was under suspicion.
"He demonstrated a sharp criminal ability and had no fear about the consequences of his behavior," said a police statement.
"On one occasion Davide De Vita even said he wanted to set off a bomb so as to take the money available if the emergency vehicles needed to be repaired," it added.
Temperatures in Sicily have been hitting 40 degrees Celsius regularly this summer and the land is parched and easy to set alight.
In 2016 Israel arrested a record 24 people for starting wildfires across the country.
In the 1980s up to 2,000 fires in California were believed to have been set by the same man, dubbed the Pillow Pyro.
But in 1991 when he was arrested, he turned out to be John Orr, a firefighter and senior arson investigator.
He was convicted of killing four people during a blaze at a hardware store in South Pasadena in 1984 and, now 68, is still serving a life sentence.
Sweden was hit by an arson epidemic in 2016, involving cars being set on fire.