CHICAGO -- An attorney for R. Kelly is asking a federal judge to reconsider his decision to keep the singer behind bars while he awaits trial in a child pornography case in Chicago.

The Chicago Sun-Times reports that attorney Steve Greenberg told U.S. District Judge Harry Leinenweber in a court filing that court personnel could monitor Kelly's activities if he's place on home confinement. Prosecutors have expressed concerns that Kelly might try to contact witnesses if he's freed.

The charges against Kelly also include coercing minors to engage in sex. He faces similar federal charges in New York.

In his motion, Greenberg said that the monitoring coupled with limiting Kelly's internet access would make it "virtually impossible to contact any witnesses without being caught."