R Kelly has been charged with 11 new counts of sexual assault and abuse.
Some of the fresh charges carry a maximum jail term of 30 years, making them the most serious the R&B singer faces.
They relate to alleged sex crimes against a minor aged between 13 and 16.
Among the charges are two counts of criminal sexual assault by force, two counts of aggravated criminal sexual abuse and three counts of aggravated criminal sexual abuse.
Kelly also faces four counts of aggravated criminal sexual assault, which carry a maximum prison sentence of 30 years.
He was already facing 10 counts of aggravated sexual abuse involving four women.
Three of the alleged victims in these cases were minors when the alleged abuse occurred
Kelly pleaded not guilty to the original charges and denied any wrongdoing after his arrest in February.
The singer’s defence attorney, Steve Greenberg, said he had received word of new charges from prosecutors but had not seen any filings.
“We’ll see what the charges are, and we’ll proceed accordingly,” Greenberg told The Chicago-Sun Times.
“I know this much: it’s old. They’re allegations from years ago.”
According to the new court filing, the first eight counts are from encounters that allegedly occurred in January 2010.
Three others relate to alleged encounters between May 2009 and January 2010.
Agencies contributed to this report
