A man says he was blinded by the sun's reflection on the water before his jet ski collided with his girlfriend's and killed her on a Thai resort island.
Thai police are expected to launch an investigation into the death of Australian woman Emily Jayne Collie, 20, following the accident on Phuket on Sunday.
Ms Collie, from Kyabram in central Victoria, died from severe injuries after her jet-ski collided with one hired by her boyfriend, Tommy Keating, just before sunset at Kata Beach.
Thai life guards reportedly dragged the 20-year-old student from the water and performed CPR for 15 minutes in a bid to revive her.
She was taken to Chalong Hospital where she was pronounced dead on arrival as a result of neck and shoulder injuries.
It's understood a police investigation will follow, with Mr Keating expected to be questioned.
"The bigger issue is clear, is about the cause of the accident," a legal source in Phuket told AAP.
Mr Keating told Thai authorities his vision was blinded by sunlight reflecting off the sea.
After hearing the tragic news on Monday, Ms Collie's friends expressed their shock on Facebook.
"Cannot even accept that this has happened," Ms Collie's friend Steph Hanlon wrote
"Such a beautiful and strong girl and I feel so blessed to have once been so close with you. Emily Jayne Collie you will forever be loved, hope there's a nice big trampoline up there for you xxxx."
Mr Keating's sister, Bree Lyon, told Fairfax Media the family was "absolutely devastated" about the death of "our darling girl with those beautiful curls".
"From the very moment I met you I loved you, I cherished your genuine heart, and that beautiful smile," Ms Lyon said.
Ms Collie was a student at Charles Sturt University and had attended Goulburn Valley Grammar School in Shepparton, according to her Facebook page.
DFAT through its travel advisory, warns Australians over the safety and risks of riding jet-skis and motorcycles in Thailand amid claims of extortion by operators, as well as insurance coverage.
Australians are regularly warned over hiring jet-skis, especially those without adequate experience.
"There have been many serious accidents involving jet-skis and motorcycles in Thailand," DFAT says.
It later confirmed it was "providing consular assistance to the family of an Australian woman who died in Phuket".
