In Australia, one of the most costly crimes is the deliberate setting of bushfires.

Police, firefighters and researchers state that not much is known about what is the motivation of arsonists and what should be done to tackle the crime.

A conference starting today in Melbourne hopes to figure out how to control bushfire arson.

According to Monash University researchers, half of OZ's bushfires are lit knowingly. Yet Dr Janet Stanley from the university said that little was known about bushfire arson.

She said, "It's quite strange in some ways why Australia hasn't put more funding into understanding what is probably the most costly crime in Australia. It has so many profound impacts on people. And if we could solve and reduce this considerably then a lot of the distress that's caused by bushfires would be lessened."

Those gathering in Melbourne are police, firefighters, academics and psychologists to try and develop a plan to cut down the number of deliberately lit fires.