No official conclusion has been reached on four fires in the past week on Rarotonga, with Cook Islands police saying investigations are ongoing.
A substation of the country's only telecommunications provider Bluesky was the first to go up in flames, another business premise was damaged, then a residential home and a large storage shed were completely destroyed.
The most recent fires are similar to a pattern that began in 2012 when multiple businesses, schools, private and government homes went up in flames, leading to speculation the fires were deliberately lit.
A $US13,380 government reward offered in 2012, for the apprehension and conviction of the suspected arsonist, remains unclaimed and the causes of most of the fires are still unsolved.
Police have said it's fortunate no one has died in the fires.