The disgraced singer's lawyer filed docs, obtained by TMZ, asking the judge to release his client pending his trial and claiming the Bureau of Prisons failed to disclose Kelly's medical tests from March showing he is "likely diabetic."

In docs, Kelly's lawyer also claims the singer has high cholesterol and high blood pressure ... further putting him in a vulnerable position if he contracts the deadly coronavirus while penned up at MCC Chicago.

The judge has not yet made a decision on whether to release Kelly. TMZ broke the story ... he swung and missed TWICE last month. During Kelly's first attempt, the judge denied him saying, among other things, the singer is a flight risk. Not long after, his team made a second attempt, but again, the judge said no dice.

The judge had previously expressed concern Kelly might intimidate witnesses if he's allowed out of jail. Kelly addresses that in the new docs, referring to one of his former girlfriends who used to visit him regularly in jail and correspond with him. He says during all those visits he was well aware she is one the Jane Doe victims in his case, and still never attempted to obstruct justice.

He doesn't name her, but our Kelly sources tell us he's talking about Azriel Clary, who's now working with the prosecution. Kelly says if he had tried to intimidate her, she would have reported him to prosecutors by now.