Cardiff Blues have confirmed that centre Owen Williams has suffered a "significant injury to his cervical vertebrae and spinal cord."
The 22-year-old, who has played four times for Wales, was injured playing for Cardiff Blues at the World Cup 10s on Sunday.
The region said that he underwent an operation on Monday to stabilise a fracture and is currently recovering in hospital in Singapore.
His family and Blues staff are with him in hospital, and arrangements are now being made to arrange his safe transfer home "at an appropriate time."
The region and Williams' family have also thanked hundreds of people who have offered messages of support.
More top news
Gareth Bennett AM has caused outrage amongst his peers and the transgender community after commenting about the rights of minority groups.
Some brighter spells in between, especially later in the day but feeling cold despite higher temperatures than recent days.
The Met Office has issued a yellow 'be aware' weather warning of ice for parts of Wales overnight and into tomorrow morning.