Indonesian police are searching for four Australians who flew out of Bali the day after allegedly assaulting a Perth father who died in hospital on Thursday evening.

Paul Dougan, from the south-eastern Perth suburb of Gosnells, underwent three surgeries, including to have his spleen removed, after the attack on August 5.

A statement from Denpasar City Police revealed Dougan was allegedly attacked while at the One Tribe One Life Lounge and Cafe in Kuta in the early hours of August 5.

Dougan had allegedly reprimanded an Australian man for hitting a woman when the man, along with four others, turned on him.

He sought medical treatment at Kuta’s Murni Teguh Hospital three days later, before being transferred to the BIMC Hospital for further treatment.

However, Dougan died at the hospital 12 days later.

His family rushed to Bali to be with him and on Wednesday his son Liam launched a GoFundMe page to help pay for mounting medical costs.

On the fundraiser, Liam wrote that his father had undergone three surgeries, including to have his spleen removed, and his injuries included 10 broken ribs and severe internal bleeding.

In the statement released on Friday, Denpasar Police said investigators had questioned a number of witnesses, including Dougan’s family, security and staff at the bar, and were examining CCTV of the night.

Police suspected four Australian nationals of being linked to the incident – identified only by the acronyms RGG, PAM, JRM, and TRZ – and immigration records “indicate that all four individuals departed Indonesia on August 6”.

“Their departure is a key fact currently being investigated, alongside details regarding their respective whereabouts at the time of the incident, their roles in the event, their relationships with one another, and the sequence of activities before and after the incident,” the statement read.

Denpasar City Police Chief, Senior Commissioner Leonardo David Simatupang said police would handle the case professionally, transparently, objectively and based on evidence, and urged the public to refrain from spreading unverified information.

“We will clearly uncover the sequence of events, including the roles of each party and the cause of the victim’s death,” he said.

“The legal process will be conducted professionally and in accordance with statutory regulations.”

Dougan’s friend David Coughtrie told 9News Perth the father’s death was “just devastating”.

“He’s not the kind of guy to go looking for that sort of trouble,” Coughtrie said.

“He’d grabbed his partner and said, ‘Let’s get out of here’. As he stood up he was confronted by a person that said, ‘What did you say?’ and pretty much didn’t wait for an answer and just struck him.”

On the fundraising page, Liam wrote his father was “brutally assaulted by a group of Australians who are yet to be identified”.

“They beat and kicked him multiple times putting him in a life-threatening condition,” it read.

“From this Paul suffered internal bleeding and 10 broken ribs, has undergone three major surgeries, had his spleen removed, required four blood transfusions, and currently has drains in both his lungs and abdomen as a result of the internal injuries and bleeding from the attack.”

As of Friday, the fundraiser had received more than $68,000 in donations.

WA Premier Roger Cook said the matter was one for the Australian Federal Police to assist with, and warned that, when travelling overseas, tourists face the full force of other countries’ legal systems.

“It obviously sounds like a very violent and horrific event, and that family must be hurting, so our thoughts are with them,” he said.

Gosnells Hawks Football Club posted on social media on Friday acknowledging Dougan’s death with “great sadness”.

“Paul was a much loved father, grandfather and member of the wider Gosnells community, and his loss will be deeply felt by all who knew him,” the club wrote.

“On behalf of everyone at the Gosnells Football Club, we extend our deepest condolences to Paul’s children and their partners, his grandchildren, family and loved ones during this incredibly difficult time.

“Our thoughts are with the entire Dougan family, and we hope they find strength and comfort in each other and in the love and support of those around them.

“The entire Gosnells Football Club community stands with you during this heartbreaking time.

“Rest in peace, Paul.”

The Department of Foreign Affairs and Trade has been approached for comment.

With 9News Perth