The allegations against the latest military official accused of sexual assault include claims that he may have arranged for a woman to engage in prostitution, sources say.
The charges have sparked outrage on Capitol Hill, as it emerged the accused soldier, whose name has not been made public, was assigned as a coordinator of a battalion-level sexual assault prevention program at Fort Hood. He has been suspended from all duties but has not been charged with any crime.
It is the second time in the last month that a military official who led a sexual assault prevention unit was accused of sexual assault.
The nature of the accusations is still unclear. A source on Capitol Hill told Fox News the investigation includes allegations of forcing one woman into prostitution and sexually assaulting two others.
A defense official told The Associated Press the allegations include a claim that the soldier may have arranged for one of the women to have sex for money. This official said it's not yet clear whether the woman was forced into that arrangement.
George Little, spokesman for Defense Secretary Chuck Hagel, said Hagel has informed President Obama about the accusations against the Army sergeant first class, and Obama made clear he wants the behavior stopped.
Little told reporters that Hagel's staff is working on a written directive that will spell out steps aimed at resolving a problem that has outraged lawmakers.
"The president has made very clear his expectations on this issue," Little said.
Lawmakers are calling for changes in the wake of the allegations.
Sen. Claire McCaskill, D-Mo., and Sen. Jeanne Shaheen, D-N.H., on Wednesday called for Hagel to create a tougher review process for individuals applying for sexual assault prevention unit positions.
"This crisis has reached a breaking point that requires more than the traditional process for filling military jobs," they wrote in a letter Wednesday.
Rep. Adam Smith, D-Wash., the top Democrat on the House Armed Services Committee, said in a statement: "This latest incident clearly demonstrates that the military's efforts to prevent sexual assault are failing miserably."
The case, along with another one involving an Air Force officer, highlights a problem that is drawing increased scrutiny in Congress and expressions of frustration from Hagel.
"This is sickening. Twice now, in a matter of as many weeks, we've seen the very people charged with protecting victims of sexual assault being charged as perpetrators," Sen. Patty Murray, D-Wash., said.
Hagel said he was directing all the services to retrain, re-credential and rescreen all sexual assault prevention and response personnel and military recruiters, Little said after Tuesday's announcement that the Army sergeant was accused of pandering, abusive sexual contact, assault and maltreatment of subordinates.
The soldier was being investigated by the Army Criminal Investigation Command. No charges had been filed, but officials say they expect them fairly soon.
Little said Hagel was angry and disappointed at "these troubling allegations and the breakdown in discipline and standards they imply." He said Hagel had met with Army Secretary John McHugh and ordered him to "fully investigate this matter rapidly, to discover the extent of these allegations and to ensure that all of those who might be involved are dealt with appropriately."
The Fort Hood soldier had been assigned as an equal opportunity adviser and coordinator of a sexual harassment-assault prevention program at the Army's 3rd Corps headquarters when the allegation arose, the Army said.
House Armed Services Committee Chairman Howard P. "Buck" McKeon, R-Calif., said in a statement he was "outraged and disgusted by the reports out of Fort Hood."
Just last week an Air Force officer who headed a sexual assault prevention office was himself arrested on charges of groping a woman in a Northern Virginia parking lot.
Sen. Carl Levin, D-Mich., chairman of the Senate Armed Services Committee, said his panel was considering a number of measures to counter the problem, including changes to the Uniform Code of Military Justice, and will act on them next month.
Sen. Kirsten Gillibrand, D-N.Y., said she intends to present new legislation on Thursday to overhaul the military justice system by removing chain-of-command influence from prosecution of sex abuse crimes.
The Pentagon is struggling with what it calls a growing number of sexual assaults across the military. In a report last week, the Defense Department estimated that as many as 26,000 military members may have been sexually assaulted last year, based on survey results.
Of those, fewer than 3,400 reported the incidents, and nearly 800 of those simply sought help and declined to file formal complaints against their alleged attackers.
There also is an ongoing investigation into more than 30 Air Force instructors for assaults on trainees at Lackland Air Force Base, Texas, as well as the recent arrest of the Air Force's head of sexual assault prevention on charges of groping a woman.
An Arlington County, Va., police report said Air Force Lt. Col. Jeffrey Krusinski was drunk and grabbed a woman's breast and buttocks in a parking lot earlier this month. The woman fought him off and called police, the report said. A judge has set a July 18 trial date for Krusinski.
Such cases and two recent decisions by officers to overturn military juries' guilty verdicts in sexual assault cases has precipitated a storm of criticism on Capitol Hill.
McCaskill is holding up the nomination of Air Force Lt. Gen. Susan Helms, tapped to serve as vice commander of the U.S. Space Command, until McCaskill gets more information about Helms' decision to overturn a jury conviction in a sexual assault case.
The Associated Press contributed to this report.