WASHINGTON — Youth boot camps and their referral services are using deceptive marketing practices when trying to convince parents of troubled kids to try the programs, a federal investigation has found.

The programs — also referred to as residential treatment facilities, behavior modification programs or therapeutic boarding schools — have been under congressional investigation for about a year. It's estimated that at least 20,000 U.S. teens attend such facilities.

As part of the review, investigators at the Government Accountability Office made undercover calls to boot camps and referral services that work with them.

In one case, an investigator posing as a father was advised to hide information from his wife about a program, according to GAO investigator Greg Kutz, who was scheduled to testify about the investigation today before a House committee.

"The referral agency warned our fictitious parents that his wife might 'freak out' about sending her daughter to a boarding school, and stated: 'I want you to tell her that it's a college prep boarding school. ... If she thinks that you want to send her daughter to a place where there are drug addicts and people that are all screwed up, she will look at you and say 'no way,'" Kutz said in prepared testimony obtained by The Associated Press.

Kutz also stated that when investigators called a Texas wilderness therapy program, they were misled by a program representative into thinking health insurance would reimburse the family's expenses upon completion of the program.

The person "emphasized that we should not call ahead of time to seek pre-approval, because then we would be 'up the creek,'" Kutz said. Experts told investigators that insurers actually could require pre-approval before mental health services are provided.

Today's hearing is a follow-up to one last fall in which Kutz said GAO uncovered thousands of allegations of abuse, some of which involved death, at residential programs since the early 1990s. The agency planned to detail eight individual cases, including that of a 16-year-old with asthma and chronic bronchitis whose complaints of chest pain and breathing problems were dismissed by staff at an Arizona boot camp. The boy ended up dying from empyema, a condition in which pus accumulated in his chest. An autopsy found more than 70 injuries, including some from blunt force, on the boy's body.