While Chicago police continue to investigate allegations that R. Kelly had sex with an underage girl, the R&B singer is proclaiming his innocence.

The allegations are based on a videotape, anonymously mailed to the Chicago Sun-Times, that allegedly shows nearly 27 minutes of Kelly having sex with a teenage girl. The paper has given a copy of the tape to police (see "R. Kelly Under Investigation After Sex Tape Surfaces").

The seeming scandal, though, didn't prevent the singer, whose real name is Robert S. Kelly, from performing at the opening ceremony of the Winter Olympics on Friday. Before he took the stage, he told Chicago television station WMAQ that the allegations were false. "It's very difficult for me, but you know, I'm innocent," Kelly said. "So it's not that difficult. It's crap, and that's how we're going to treat it."

Kelly's lawyer, John M. Touhy, released a statement on Monday saying that the tape is a fabrication. "No videotape of Robert Kelly having sex with an underaged girl exists, and any such statements that there is such a videotape are false and malicious," the statement reads. The statement goes on to say that the timing of the video should be questioned, calling it a "blatant attempt to do as much damage to Robert Kelly as possible."

Why would someone create a false tape to slander Kelly? The singer has a theory. He told WMAQ, that it could have been made by a former employee who attempted to blackmail him previously and who may have released it to ruin the singer's big moment at the Olympics.

"The reason these things are happening, I really do believe, is because of the fact that I didn't fall back as far as blackmail was concerned," Kelly told the station. "I didn't give them any money. ... All I know is this — I have a few people in the past that I've fired, ... people that I've thought were my friends that's not my friends. Ever since then, it's been threats on what they're gonna do to me, and ... if I don't pay them this, they'll put a story out ... and when I refuse to pay them, and now here come this story. ... The world is getting ready to watch me sing a song called 'The World's Greatest,' and you've got a tape out there trying to ruin my career."

The tape isn't the only source of allegations, however. Kelly must appear in court on February 21 in Chicago to face charges that he had sex with a separate underage girl, Tracy Sampson, who filed a $50,000 civil suit in August. Sampson claims that during her internship at Epic Records, Kelly took advantage of his position of authority and induced her into a sexual relationship that lasted from May 2000 to March 2001, even though he was married and knew she was 17.

Sampson's lawyer, Susan E. Loggans, previously represented yet another alleged victim of Kelly's, Tiffany Hawkins, who claimed Kelly had sex with her while she was underage. In 1998, Kelly settled Hawkins' civil suit for a reported $250,000. Hawkins claimed that when she was 15, the singer not only had sex with her but induced her to have group sex with other teenage girls.

Loggans said the family of the girl in the sex tape has contacted her, but the lawyer couldn't discuss whether she would be taking on the case. She did say, though, the three Chicago cases are not as separate as they may seem, since some share witnesses.

The investigation will not affect the March 26 release of Kelly's joint album with Jay-Z, The Best of Both Worlds, his label said.