Kyabram woman Emily Collie, 20, was killed when the holidaying couple's jet-skis crashed at high speed in waters off Phuket on Sunday.

Mr Keating, 22, told police that strong sunlight reflecting from the sea made it impossible for him to see the jet-ski being ridden by his girlfriend.

Thai police have said Mr Keating will be charged with reckless driving causing death.

Emily Collie's parents landed in Phuket on Wednesday and it's believed they met with senior police officials at the police station shortly after arriving.

Seven News reported Ms Collie's parents told police they did not wish to press charges against Mr Keating.

Mr Keating may face a two-year suspended sentence, which means he may be allowed to return home, but only after facing court.

On Tuesday, Mr Keating's sister Bree Lyon said the family was in Thailand with him .

She said: "Right now he is co-operating with authorities, it was an absolute accident."

Mr Keating took to Facebook on Monday to express his heartbreak over losing his girlfriend.

"I'm so broken and I know I'll never never be able to mend ... I'll always be your boy and you'll always be my girl! We had so many plans for our future Emmy," he wrote.

On Tuesday, Ms Collie's older sister Jessica posted her own emotional tribute.

"My beautiful princess, my twin, I'm lost. My heart has the biggest hole in it and I don't know how it will ever be filled," she wrote.

"I cannot even begin to explain the sadness and loneliness I feel right now.

"I am beyond proud of you Em and I'm really going to miss you more than you could possibly imagine. You have touched so many hearts. I'll love you until the end, rest your beautiful soul my darling baby sister."

Jessica Collie's tribute to her baby sister, Emily. Photo: Facebook/@jessica.collie