Singer R Kelly pleaded not guilty to 21 counts of producing child pornography at a court hearing in Chicago on Wednesday.

The R&B star, who was released on $750,000 (�513,500) bail after his arrest on 5 June in Florida, is accused of appearing in a video showing him having sex with an underage girl.

The video has been widely distributed in the US and over the internet. Mr Kelly says he is not the man on the 26-minute tape.

If found guilty, Mr Kelly could face up to 15 years in prison and a fine of up to $100,000 (�68,500).

Another hearing was set for 7 August and Mr Kelly remained free on bond, as he has been since shortly after his arrest.

R Kelly is a Grammy Award-winning artist

Mr Kelly, whose first name is Robert, made no statement during his court appearance.

But he smiled and waved to fans who lined the corridor of the Cook County Courthouse, many of whom wore T-shirts reading: "R Kelly We Luv You."

Sam Adam, one of the singer's lawyers, told reporters outside the court that his client was innocent.

Song

Cook County State's Attorney Richard Devine says the video was made in November 1997 or later and that the girl involved was born in September 1984.

A week ago, the Grammy Award-winning singer released a song to a Chicago radio station stating his innocence.

R Kelly: Hit with a string of legal cases

In the song, Heaven, I Need A Hug he criticises his detractors and says he hopes to regain his fans' support.

His defence lawyer, Edward Genson, says he will prove that the woman on the tape was not younger than 18.

Mr Kelly - who was discovered busking in the Chicago underground system - has become a best-selling singer and producer.

His best-known songs include I Believe I Can Fly and If I Could Turn Back the Hands of Time, and he has worked with Michael and Janet Jackson.

Controversy

Chicago is Mr Kelly's home town. Following his arrest, one of Chicago's top music stations dropped his music from its playlist.

A survey of local residents showed that 56% of people thought all radio stations should do the same.

The R&B star has been ordered to avoid contact with children he is not related to and to check in with police once a week.

He has been hit with a string of legal cases from women who say the star had sex with them when they were below the legal age of consent.