2/24/19 -- Sources connected to R. Kelly tell us the singer could be behind bars until at least Tuesday, if not Wednesday. The reason ... the slow-moving wheels of bureaucracy. We're told R. Kelly's lawyers plan on heading to the Child Support Bureau on Monday to figure out exactly how much their client owes in back pay. Once they do that, they'll head to the bank, pull out the necessary funds and pay off his bail and child support payments in one shot. That technically would lift the hold on his bond, but our sources say it could take 24 to 48 hours to process the paperwork. In other words ... Kels might be sitting in a jail cell 'til mid-week.

7:30 PM PT -- R. Kelly reportedly failed to post the $100k bond by the cutoff time of 9 PM in Chicago, so he'll have to spend the night in jail.

2:10 PM PT -- We're told until R. Kelly makes bail, he's being held in a holding pen by himself because the jail doesn't want him interacting with other inmates for safety reasons. R. Kelly's considered a "high profile individual," and if he doesn't bond out tonight he'll be placed in his own cell.

TMZ's also obtained video of Joycelyn and Azriel leaving the courthouse. Neither woman had anything to say about Kelly's case or their relationship with their parents.

1:15 PM PT -- As we told you ... Joycelyn Savage and Azriel Clary were both in the courtroom for R. Kelly, and were reportedly sitting in the first row reserved for friends and family during his hearing. The women are allegedly the singer's "sex slaves," but both have denied that. They were seen holding hands entering court together.

12:25 PM PT -- TMZ's obtained a courtroom sketch of R. Kelly and his lawyer, along with the State's Attorney, in front of Judge John Fitzgerald Lyke Jr.

12:00 PM PT -- R. Kelly's lawyer just had a heated exchange with a reporter, who called him out for allegedly misquoting one of the victims. The lawyer shot back and accused the guy of trying to sell books, and that's when it got really testy ... and an F-bomb was dropped.

Greenberg also says R. Kelly should be able to bond out, but it might take a while because his financial situation is complicated ... and it's Saturday. As far as R. Kelly's defense, Greenberg says he's not ready to divulge info about that yet because he's in the process of reviewing all the evidence.

He did raise eyebrows at the end of his Q&A, though, when he said about R. Kelly -- "He's a rock star, he doesn't have to have nonconsensual sex."

11:35 AM PT -- Cook County District Attorney Kim Foxx just gave more details of the alleged sex crimes to the press outside the courtroom, and says 2 of the 4 alleged victims turned in physical evidence -- shirts with R. Kelly's semen on them -- to prosecutors.

Avenatti also spoke to reporters and started by blasting R. Kelly's lawyer, Steven Greenberg. Avenatti says Greenberg has referred to all of the alleged victims as "liars" and insists the new sex tape is the same as the one from 2008, which Avenatti says is a lie.

He also claims R. Kelly's handlers were at the courthouse to keep Azriel Clary's parents away from her and believes Azriel has been brainwashed.

R. Kelly just appeared before the judge, who set his bail at $1 million ... meaning the singer can be released -- but only if he can afford it.

Prosecutors laid out the details of R. Kelly's 4 separate indictments Saturday at the Leighton Criminal Court Building in Cook County, and requested the R&B singer not be granted bail ... but the judge disagreed and set bail at $250k for each indictment.

The judge also ordered Kelly to surrender his passport.

R. Kelly's lawyer reportedly said the singer's finances are a mess, so he can't bond out just yet. However, a source close to Kelly tells us he'll be able to gather up $100k soon and post bail. If he does, he'll be released from jail ahead of his trial.

As we reported ... R. Kelly surrendered to police in Chicago Friday night, turning himself in at a police station after being charged with sexual abuse of 4 girls, at least 3 of whom were minors.

Prosecutors hit R. Kelly with 10 counts of aggravated criminal sexual abuse Friday morning, and 9 of the 10 counts involve alleged victims ranging in age from 13 to 16 years old. There are 4 alleged victims in total, and according to the criminal complaint ... the graphic allegations include oral and vaginal sex with a girl between the ages of 13 and 17.

Attorney Michael Avenatti -- says he's representing at least 1 of the alleged victims in the R. Kelly indictment -- was on hand for Saturday's court hearing. He arrived with the parents of Azriel Clary, one of R. Kelly's alleged sex slaves.

Both Azriel and Joycelyn Savage -- another one of R. Kelly's alleged sex slaves -- were inside the courtroom for the hearing ... but it's unclear if they had any contact with their parents.

As we reported ... Avenatti also claims the new sex tape he turned over to prosecutors shows R. Kelly engaging in sex acts with a 14-year-old girl. He released images from the video Friday, showing what appears to be R. Kelly.