Comatose since he suffered a skiing accident in March, Dutch Prince Johan Friso has been showing signs of "minimal consciousness", the royal family says.
In a statement, the Dutch Royal House said that "it will take many months before there is more clarity" about the prince's chances of recovery.
It gave no further details, but urged the media "to continue to respect the privacy of the family."
The 44-year-old prince, buried by an avalanche in Austria Feb. 17, is being treated at a London hospital. He was transferred there in March.
The accident occurred as Friso was skiing off-piste in Lech, Austria, despite avalanche warnings, with a childhood friend from the alpine village that the Dutch royal family had been visiting each winter for years.
The friend was carrying an avalanche "air bag" and escaped without serious injury. Friso was found after 25 minutes with the help of a signaling device he was carrying and was flown by helicopter to an Innsbruck clinic.
Doctors there told a news conference last spring that it took nearly 50 minutes to reanimate the prince after he was pulled from the snow and "oxygen starvation has caused massive brain damage to the patient."
Friso, the second son of Queen Beatrix, is not in the line of succession because he married without the government's permission. He and his wife, Mabel, had been living in London with their two daughters.