HOUSTON -- Five people were arrested and accused of turning teenagers into prostitutes, KPRC Local 2 reported Tuesday.

The four men and one woman were apprehended in several parts of Houston late Monday and early Tuesday.

One of the suspects is a former Houston police officer. John Butler joined HPD in 1985, but only stayed seven months before leaving the force while he was still on probation.

A sixth suspect, Ronnie Presley, lives in Tulsa, Okla. Officials said he managed to escape when police came after him Monday night. Presley is considered armed and dangerous.

The suspects are accused of running a sex trafficking operation in Houston that forced girls as young as 16 into prostitution. The girls were held against their will at three Houston massage parlors in what investigators describe as deplorable conditions.

At least four teenagers were allegedly forced to work as prostitutes through threats and violence.

"Through physical beatings, threats at gunpoint, threats to harm family members and even promises of love and affection, the defendants would control these children and use them as personal financial assets," said Tim Johnson with the U.S. attorney's office in Houston. "These defendants are charged with effectively turning four 16- and 17-year-old children into indentured sex slaves."

Investigators said the prostitution ring began operating in May 2005.

The FBI said women and girls were transported between Texas, Florida, Kansas, Arizona and Nevada to be sold for sex.

One teenage girl was rescued during the investigation. Several other girls and women have been returned to their families, according to the U.S. attorney.

"Tragically, traffic in children is growing and it is strong," said Richard Powers, Houston FBI Special Agent In Charge.

The suspects face charges including sex trafficking by force, sex trafficking of children, and transportation of minors. The charges could put most of the accused behind bars for life if they are convicted.

The investigation was conducted by the Houston Innocence Lost Task Force. It a special group that targets child prostitution with officers from the FBI, Houston police, and the Texas Attorney General's Office.

"Since 2004, the Houston working group has recovered over 100 child victims. Over 30 of those victims alone were recovered this year," Powers said.