Several football players at the US naval academy are under investigation on allegations they raped a female midshipman at a party last year, officers said Friday.

The case highlighted a growing crisis over sexual assaults in the military's ranks and comes a week after President Barack Obama spoke at the academy, warning the problem threatened to undermine discipline in the armed forces.

Naval criminal investigators were examining the allegations lodged against three football players at the naval academy in Annapolis, Maryland.

Pentagon spokesman Colonel Steve Warren said "the naval academy leadership is monitoring this" and "they're evaluating all the options for adjudication."

The New York Times, which first reported the case, said no charges have been brought against the football players so far.

The academy delayed the graduation of one of the three players and his commissioning as a naval officer has been postponed, the paper wrote.

The probe marked the latest in a wave of embarrassing, high-profile sexual assault cases that have reached into the elite American academies, where future military leaders are trained and educated.

A court-martial proceeding began this week for an instructor at the naval academy on allegations he raped a female midshipman.

At West Point, the US Army's academy in New York state, a sergeant faces allegations he secretly filmed female cadets without their consent, including when they were in the shower.

In Texas, a soldier who worked in a rape prevention program has been accused of forcing a subordinate into prostitution.

And an Air Force officer in charge of his service's sexual assault prevention office was recently arrested near the Pentagon for allegedly assaulting a woman.

A Pentagon report this month showed a rise in reported sexual assaults and other "unwanted sexual contact" over the past two years.

Defense Secretary Chuck Hagel has voiced alarm over the cases and vowed to get the problem under control.

"He is very concerned about the increase in sexual assault cases in the department. And it's completely unacceptable. And we're going to do everything we can to stamp it out," Warren said.

Next week, the chairman of the Joint Chiefs of Staff and the heads of all five military branches will make a rare appearance together before lawmakers to testify on the issue and proposals to address it.