Family confirms that the teenager died on 26 December but did not reveal the cause of her death.
The death of 18-year-old rising MMA star Victoria "The Prodigy" Lee, announced at the weekend, has prompted an outpouring of tributes from people associated with the sport.
Asia-based ONE MMA Championship chief Chatri Sityodtong said he was "heartbroken" by Lee's passing and that he would remember her "for the beautiful and precious soul that she was".
"I first met Victoria when she was 11 years old. I watched her blossom over the years as a martial artist and a human being," Sityodtong wrote on his Facebook page on Sunday.
Indian-Canadian mixed martial arts star Gurdarshan Mangat tweeted: "She was destined for greatness. I just pray she knew that before she left us. That she truly was a light."
This one is tough . Her energy was felt whether you knew her or not . She was destined for greatness . I just pray she knew that before she left us . That she truly was a light 🙏🏾 @ONEChampionship https://t.co/8gTzxyyfK0— Gurdarshan “Saint Lion” Mangat (@saintlion) January 8, 2023
Lee came from a family of champion MMA fighters - her older sister Angela is the ONE Championship atomweight world title holder while her brother Christian holds the ONE lightweight title.
Lee died on Boxing Day but was only announced late Saturday by her sister Angela on Instagram.
"We miss you so much sis. More than you could ever realise," Angela wrote.
"We're all broken. Because a piece of you was in each of us and when you left, those pieces were ripped out of us. We will never be the same."
The cause is not revealed
The cause of death was not revealed by her family.
Lee was born and raised in Hawaii to a Singaporean father and South Korean-Canadian mother and fought under the Singapore flag.
She had her first MMA fight at 16 and her last bout was in September 2021.
Victoria Lee had been tipped to join her siblings as a world champion and was nicknamed “The Prodigy”.
According to the ONE website, the young Lee had put competition on the back burner in 2022 to focus on graduating from high school, but she had planned to make a big return in 2023.