Ashton, who lived in south London, died from a stray bullet shot wound while he was partying at Zoom Bar in famed backpacker haunt Koh Phangan on New Year’s Eve.
The Bangkok Post reported the 22-year-old died in hospital from a wound to his torso.
The Foreign Office is providing consular assistance to his family.
Thai police have arrested a man, who the Post reports admits to being involved in a fight between to groups on NYE, but not to shooting Ashton.
Tributes have flooded the popular young stock broker’s Facebook page.
“Still in shock! Can’t believe it!” wrote his friend Amy Murrell. “U always had a way to make everyone smile!”
Jospeh Brazil wrote: “R.I.P Stephen, such an amazing young man with so much talent! Gone but not forgotten!
Daniella Murrell “Heaven has gained another angel but we are all left at a loss… You are an amazing person & you will never ever be forgotten.
Image via Facebook