Two army cadets “waterboarded” a colleague at the prestigious Royal Military Academy Sandhurst, a court martial has been told.

The officer cadets Jonathan Cox, 25, and Edward Wright, 24, allegedly put a field dressing over Edward Flower’s nose and mouth and poured water over his face. Flower said the alleged attack led to mental health problems and he had to spend a week in a medical centre.

Cox and Wright, who are on trial at Bulford military court in Wiltshire, told military police the incident was nothing more than “jovial high jinks” and deny battery.

The pair confronted Flower in a corridor in August last year, the court was told. Flower claimed he tried to escape by crawling through Cox’s legs but he was grabbed by the ankles. There were two field dressings on the floor, the court was told. “Officer Cadet Wright picked one of them up and stated: ‘Let’s waterboard him,’” Flower alleged.

Flower described the dressing being placed across his eyes, nose and mouth, tight enough to stay in position. Cox picked up a water bottle and poured water over the alleged victim’s face, it is claimed. “It was a suffocating motion, being completely blindfolded you didn’t have any sense of what’s really going on,” Flower said. “It made me feel massively dehumanised.”

Flower said Wright pulled back the field dressing to reveal his nose and mouth, keeping his eyes covered. Wright then poured the bottle of water over his exposed nose and mouth for 15 to 20 seconds, he alleged. He estimated that about 500ml of water was poured over his face in total.

Flower, now a second lieutenant serving with the Royal Gibraltar Regiment, said he felt distressed and vulnerable during the incident, which ended when a colleague emerged in the corridor.

He said it had a heavy effect on his mental health, leading him to put in his resignation at one point. He claimed he was ostracised by colleagues and spent a week in the medical centre due to the effect on his mental health.

Prosecuting, Col Richard Allen said Flower had been returning from a platoon meeting with his colour sergeant when he came across Wright and Cox. This meeting was called after Flower claimed Wright had been making degrading statements about him, the court heard.

In interviews with the Royal Military Police, the defendants claimed Flower had found the incident funny.

Wright said he had only poured enough water to fill a shot glass on to Flower. Cox told police that less than 20ml of water was poured on Flower’s head to wet his hair and described it as “just friends being friends”.

Allen told the court it had not been “jovial high jinks”. He said: “He was not on friendly terms with either Mr Wright or Mr Cox. It undermines the defendants’ suggestion that this was jovial banter between willing participants.”

The trial continues.