Military police are investigating claims that two cadets “waterboarded” a fellow recruit at Sandhurst.
The Sun reported two officer cadets allegedly held down an individual, covered his face with a cloth and poured water over it, creating the sensation of drowning.
The alleged incident is said to have taken place on 7 August.
Deputy Commandant of the Royal Military Academy in Surrey Brig Bill Wright said he was “aware of the allegations”.
He said he expected “the highest standards of behaviour at Sandhurst” and had therefore “ordered an investigation by the Royal Military Police”.
Anyone found to have “fallen short” of those expectations would be “dealt with robustly” – and could be dismissed, he added.
Waterboarding was used as an interrogation process by the CIA in the US, after the attacks on New York and Washington in 2001.
It was banned as an interrogation technique in 2009 by then US President Barack Obama.
Both the Duke of Cambridge and Duke of Sussex attended Sandhurst, where all officers in the Army are trained.