By Chris Lawrence, CNN
(CNN) - The U.S. Air Force has now identified at least 31 women as victims in a growing sex scandal, a four-star general said Thursday, and there might be more. The Air Force is broadening its investigation to "actively seek any others that may have been affected by this," Gen. Edward Rice, the commander of Air Force Training, said.
"We are taking a comprehensive look not only at the cases that we know, but trying to do the best we can to assess whether or not there are other cases out there," Rice told reporters at the Pentagon.
Rice said the Air Force had taken "the unprecedented step" of shutting down all recruit training for one day to give a written survey to all basic military trainees at Lackland Air Force base. The Texas base has become the focal point of the growing scandal.
One trainer has pleaded guilty to having an improper relationship with a trainee, as part of a plea agreement.
Staff Sgt. Peter Vega-Maldonado has been sentenced to 90 days in prison, 30 days hard labor and a demotion in rank and pay. In his plea deal, he also provided testimony against two other trainers who have been charged. He also said he had inappropriate relationships with 10 trainees.
The scandal came to light in June 2011, when a young female trainee came forward and accused her male instructor of assaulting her. Staff Sgt. Luis Walker now faces a general court-martial on 28 charges, including rape, adultery and aggravated sexual assault. He is scheduled to appear in court July 16.