BROWARD COUNTY, Fla. -- An unregistered convicted sex offender was arrested Wednesday for allegedly drugging and raping a 16-year-old girl.

Escorted by U.S. marshals, a barefoot Michael Webber was booked into the Broward County main jail on charges that he violated the terms of his probation.

Fort Lauderdale police said on Feb. 9 the girl reported the incident to Broward Sheriff's Office deputies. According to the girl's account, she and some of her friends were hanging out with Webber, 24, when she was given a drink and passed out. That's when the girl alleges Webber raped her.

Police suspect Webber of using the date rape drug GHB in her drink.

Police said they questioned Webber, who they said admitted to being with the girl the night of the alleged incident.

An arrest warrant was issued for Webber because he moved to Hollywood without notifying authorities and was with someone under the age of 18, both violations of his probation.

Webber had previously served time behind bars for having sex with a 13-year-old girl.

U.S. marshals arrested Webber at his grandfather's home in Fort Lauderdale.

Webber has not been charged with rape, though police said they were investigating the allegations.