The information came during an investigation launched by Vietnamese authorities to determine whether the deaths were caused by a drug overdose.

Mourners gathered at St Agatha’s Church in Cranbourne at 11.30am on Tuesday to pay their respects. The Daily Mail reports that some of Atulia’s “biker buddies”, allegedly members of the notorious Comanchero club, also attended the ceremony.

Footage posted on social media shows a white hearse carrying Atulia’s coffin, while mourners dressed in black hold blue balloons and line the access road to the church.

After the hearse passed through a procession of motorcycles and luxury cars to the cemetery, Atulia’s coffin was lowered into the ground.

On the way to the wake, many cars were seen performing a firework dance. In the evening, the deceased was bid farewell, and fireworks were also set off at the end of the ceremony.

Two of Atulia and Colivas’ Australian friends who were stranded in Vietnam following their deaths have apparently managed to escape, but the third is still alive.

According to the Herald Sun newspaper, the Department of Foreign Affairs said in a statement that it was currently providing consular assistance to one Australian in Vietnam, despite previously saying it was supporting three people.

Following the shocking events, Atulio’s family set up a GoFundMe page for the 24-year-old, writing a statement detailing the “sudden and tragic death” of their son, brother and friend.

“Vincent Atulia was 24 years old, a young man who dedicated his life to his family and friends. He was the epitome of great excellence. A young, generous heart who always cared for others before himself,” the statement said.

“Most people who knew Vincent knew that family and GOD were always the primary focus of everything he did in his short life. He gave his life to provide for and protect his loving family.”

The fund has already raised more than $60,000, with part of the proceeds going towards his funeral and “other financial matters” since Atulia failed to purchase “adequate travel insurance.”

Colivas’ brother, Nick, started a separate GoFundMe that has raised more than $44,000 to cover funeral costs and “any other financial considerations during this complicated situation.”