The Arizona Senator, 52, made the revelation during a Senate Armed Services subcommittee hearing on sexual assault in the military, CNN reported.

McSally said she did not immediately report the rape as she felt ashamed and confused, and distrusted the system. She did not offer any details about the assaults or name the senior officer who she said raped her.

"Like you, I also am a military sexual assault survivor, but unlike so many brave survivors, I didn't report being sexually assaulted. Like so many women and men, I didn't trust the system at the time," she said to the witnesses present at the hearing.

"I blamed myself. I was ashamed and confused. The perpetrators abused their position of power in profound ways. In one case I was preyed upon and raped by a superior officer."

The Senator said that years later she tried to share her experiences with senior officers but met with "wholly inadequate responses".

"I almost separated from the Air Force at 18 years of service over my despair. Like many victims, I felt like the system was raping me all over again. But I didn't quit, I decided to stay."

McSally flew an A-10 Thunderbolt II attack aircraft while enforcing the no-fly zone over southern Iraq after the 1991 Persian Gulf war. She was deployed in Kuwait in January 1995, and took command of the 354th Fighter Squadron in July 2004.

She served 26 years in the US Air Force, rising to the rank of Colonel, before retiring in 2010. She was then elected for two terms in the US House of Representatives before becoming a Senator in January.

McSally called the issue of sexual assault in the military a "deeply personal" topic for her. "We've come a long way to stop military sexual assault but we have a long way to go."

A Pentagon report for fiscal year 2017, the most recent available, found that the Defence Department received 6,769 reports of sexual assault involving service members as either victims or subjects of criminal investigation, which was nearly a 10 per cent increase over the 6,172 reports made the previous year.

But according to figures gathered in 2016, annual rates of sexual assault over the past decade decreased by half for active-duty women and by two-thirds for active-duty men.

The top Democratic member on the Committee, Senator Kristen Gillibrand, said she was "deeply affected by that (McSally's) testimony".

An Air Force spokesperson said: "The criminal actions reported today by Senator McSally violate every part of what it means to be an Airman."

"We are steadfast in our commitment to eliminate this reprehensible behaviour and breach of trust in our ranks," said Capt. Carrie J Volpe.