The ABC program spoke to a former cadet they called "Jane", who said she was raped while at ADFA. She chose to stay with the army after the assault and has watched her attacker move up the ranks, even as she continues to confront her fears.

"To walk around the corner and literally bump into him again, was awful. I didn't know how to react. I felt frightened, I felt powerless. He was standing right behind me to collect his meal.

"And that was awful, to know what he had done and to still have him standing there, laughing and joking with his mates and knowing that he's still part of the organisation that I'm in," she told Four Corners.

Jane's assault was not an isolated incident, the program said. In many cases the department had promoted officers-in-training despite having serious accusations levelled against them.

After the "Skype incident" in 2011 - when an ADFA cadet filmed his sexual encounter with another cadet and shared it on Skype - then defence minister Stephen Smith announced an external review of sexual and other abuse in the Department of Defence.

The Defence Abuse Response Taskforce established in response to that and several other reviews has amassed more than 2,400 complaints and has paid out nearly $28 million in compensation.

But Four Corners reported the department was still unsure of how to deal with alleged attackers.

Taskforce chairman Len Roberts-Smith told ABC reporter Michael Brissenden that he believed the problem was bigger than has so far been acknowledged.