21-year-old Anna Thornton, who made her World Championship debut two months ago on the road to Tokyo, is in her third year of study at the University of Washington in Seattle.
She was reportedly involved in the accident earlier this month and British Rowing say she is in a 'stable but serious condition'.
A statement from the governing body said: "We are aware that Anna was involved in an accident in Seattle, USA in early November.
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"At this time our focus is on supporting her and her family in any way possible.
"Anna's family has requested for their privacy to be respected at this time and further information will be provided when it is available."
Thornton, who hails from Nottingham, has been a dominant force at Under-23 level before recently making the leap into senior competition.
She has five World Championship medals for Great Britain at junior and under-23 level, including back-to-back quadruple sculls golds in 2017 and 2018.
Her first-ever World Rowing Junior Championships yielded bronze in 2014 and she also appeared at the Youth Olympic Games in Nanjing, China later that year.
Yaz Farooq, the University of Washington's head rowing coach, said: "The thoughts and prayers of the Washington rowing community have been with Anna since her accident.
"Our team, staff and administrators are focused on doing everything we can to ensure she receives the best possible care.
"We all miss her dearly at the boathouse and every single one of us is pulling for her."
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