Cook County prosecutors charged the Grammy award-winning R&B singer with four counts of aggravated criminal sexual assault, two counts of criminal sexual assault by force, two counts of aggravated criminal sexual abuse and three counts of aggravated criminal sexual abuse against a victim who was at least age 13 and under 17 at the time, The Chicago Sun-Times reported on Thursday.

The four aggravated criminal sexual assault counts carry maximum terms of 30 years in prison and are the most serious charges Kelly is facing.

The singer was already facing 10 counts of aggravated sexual abuse involving four women years ago, three of whom were minors when the alleged abuse occurred.

The new charges apparently relate to a single victim, identified in the court filing by the initials JP.

It isn't clear if she is the same person as one of the initial four accusers who also was identified as JP in court documents.

According to the filing, the first eight counts are from encounters that allegedly occurred from January 1-31, 2010.

Three others pertain to alleged encounters between May 1, 2009 and January 31, 2010.

Among other things, prosecutors allege that Kelly used force or threatened to do so to pressure the accuser into sex or to perform oral sex on him.

She was underage at the time, extending the statute of limitations for bringing charges to 20 years from her 18th birthday, prosecutors wrote.

Kelly pleaded not guilty to the original charges and denied any wrongdoing after his February arrest. The Associated Press couldn't immediately reach him for comment about the new charges.

Kelly's lawyer Steve Greenberg didn't immediately respond to an email seeking comment.

He told the Sun-Times he had received word of new charges from prosecutors but hadn't seen any filings in the case. He did say he understood that the allegations are "from years ago".

Australian Associated Press