NSW Police have caught 24 alleged firebugs accused of deliberately lighting bushfires in a catastrophic season that has so far killed 18 people in the state.

Almost five million hectares have burned in NSW since September, destroying 1482 homes and killing hundreds of millions of animals and livestock.

Two dozen people have allegedly risked prison sentences of up to 25 years by choosing to light bushfires, despite the potential to kill and cause millions of dollars of damage.

Rural Fire Service volunteers and Fire and Rescue NSW officers contain a small bushfire which closed the Princes Highway south of Ulladulla. (AP)

Strike Force Tronto, made up of detectives from the Financial Crimes Squad's Arson Unit, have been working closely with local police forces to catch arsonists.

Today the NSW Police confirmed 24 people had been charged over alleged deliberately-lit bushfires.

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Shocking figures released by Strike Force Tronto today also showed legal action had been taken against 47 people for allegedly discarding a lighted cigarette or match on land.

A further 53 people faced legal action for allegedly failing to comply with a total fire ban.

Police urge people to provide footage and images from phones, dashcam or other devices that show any of fires in their infancy, even if only from a distance.

Residents returned to the fire-ravaged town of Batlow today after the town was gutted by fire over the weekend. (Nine News )

A number of cows lay dead after being killed during a bushfire in Coolagolite, NSW. (AAP)

What kind of person deliberately starts a bushfire?

Most international studies have settled on a typical profile: White male, mid-20s, patchy employment record, often above average intelligence but poor academic achievement and stunted social development.

It's a disturbingly common crime, with estimates up to half the 54,000 bushfires that hit Australia on average each year are deliberately lit or suspicious.

According to a 2004 Australian Institute of Criminology (AIC) report, many arsonists are loners and suffer from mental illness.

FBI criminal profilers believe arsonists fall into three categories, defined by motivation: thrill-seekers, attention-seekers and those chasing recognition.

Arsonists driven by the need for recognition will often report the fire or be actively involved in fighting the fire.

It is not uncommon for attention and recognition seekers to stay and admire their work, while thrill-seekers are typically opportunists and likely to flee the scene.

Who is Black Saturday arsonist Brendan Sokaluk?

Australia's most notorious bushfire arsonist is Brendan Sokaluk, a former Victorian Country Fire Authority volunteer, who killed 10 people when he deliberately lit a bushfire on Black Saturday.

Sokaluk became one of Victoria's worst killers in 2009 when his fire killed 10, razed more than 150 homes and destroyed 36,000 hectares of land.

He always denied he deliberately lit the fire, instead telling police he had thrown cigarette ash out his car window.

A judge sentenced Sokaluk, then 42, to 17 years and nine months in jail.

Penalties relating to bushfires under the NSW Crimes Act, the Rural Fires Act, and Rural Fires Regulation include:

- Damaging property with the intention of endangering life – up to 25 years imprisonment;

- Manslaughter – up to 25 years imprisonment;

- Starting a bushfire and being reckless as to its spread – up to 21 years imprisonment;

- Lighting a fire when a total fire ban is in place – up to 12 months imprisonment and/or a $5500 fine;

- Not putting out a fire that you have lit – up to 12 months imprisonment and/or a $5500 fine;

- Failing to comply with a bush fire hazard reduction notice – up to 12 months imprisonment and/or a $5500 fine;

- Light or use a tobacco product within 15metres of any stack of grain, hay corn, straw or any standing crop, dry grass or stubble field – up to a $5500 fine.