A young Instagram model and influencer from Australia has died in Greece.

Sinead McNamara, 20, unexpectedly passed away while working as a crew member on the luxury yacht Mayan Queen IV.

Anchored off the port of Argostoli in Kefalonia, according to reports when the young model was found on Thursday she was in a coma.

Crew members and a doctor took Sinead back on board and made numerous unsuccessful attempts to resuscitate her. An ambulance transferred the 20-year-old to a local hospital, and she passed away while being flown via helicopter to a hospital in Athens.

“I have unfortunately received the worst news of my life, (Sinead) has passed away,” the model’s brother, Jake McNamara confirmed on Saturday.

Sinead, who was from Port Macquarie in northern New South Wales, had been working on the yacht for four months and was soon to be reunited with her mother and sister, who were on the plane headed to Greece to meet up with the model when they tragically discovered the shocking news.

“Happy birthday to the most amazing big sister I could ever ask for, 5 days till I get to see you!!! Excitement is an understatement ❤️,” Sinead wrote on Facebook on 26 August in anticipation of the reunion.

While the circumstances surrounding her death have yet to be confirmed, local media on the island have speculated that the Australian may have committed suicide.

“Local port authorities were informed at two o’clock Friday morning that the body of the woman was found hanging from a rope outside the yacht,” one local report claimed.

Meanwhile a senior officer expressed similar sentiments in an interview with The Sunday Times.

“By the looks of it, she took her life. We expect the autopsy to verify this in the coming days,” they said.

Two weeks before her death, Sinead had posted a photo of herself on a quad bike in Greece with the caption: “My head is all over the shop today. Take me back to this where my only worry was not cracking my skull open” – a post which has added to speculation that the young model may have taken her own life.

The Argostoli Port Authority is currently investigating the cause of the sudden death, and the Coast Guard of Kefalonia has ordered an autopsy.

The 92-metre-long yacht worth US$140 million, which belongs to Mexican billionaire and the chair of Mexico’s second-largest mining company, Albero Baillères was scheduled to sail off on Sunday, but was ordered to stay back due to the ongoing investigation.

All members of the crew will be interviewed by detectives followed by a forensic examination of the vessel.

Meanwhile Australia has extended support to the model’s family.

“The Department of Foreign Affairs and Trade is providing consular assistance to the family of an Australian who died in Greece,” a spokeswoman said.