It happened in the early hours of Friday along the Great Eastern Highway in Midland, in the city’s east.
“It’s possible that he sought medical attention either hours afterwards, or even days afterwards,” Senior Sergeant Andy Elliott said.
Despite an extensive search, the perpetrator remains at large, prompting police to offer a substantial reward of up to $25,000 for any information leading to his arrest.
Authorities have not ruled out the possibility the attack is linked to the ongoing “tobacco wars” observed across the country, where criminal gangs coerce businesses into selling their illicit products and retaliate against those who refuse to co-operate.
The fire caused extensive damage, affecting four neighbouring small family businesses and resulting in losses estimated to exceed $500,000.
The Midland businesses, including NC Thai Massage and Robot Bun Factory cafe, have been forced to close indefinitely, leaving their owners and employees facing significant financial hardships.
Police have intensified their investigation, urging anyone with information to come forward.