Problems are piling up for Tekashi69 as he sits in prison -- his old booking agents are threatening to sue AND claim the money he's trying to use for bail is cash he owes them.
MTA Booking is pissed at the rapper for making what it calls "malicious" and "defamatory" statements on social media and last week on "The Breakfast Club." MTA fired off a cease and desist letter demanding 6ix9ine retract and apologize publicly ... or it's gonna sue his ass.
MTA says the rapper's allegation it stole a ton of cash from him did serious damage to its reputation, and its booking agents are getting death threats.
That's not all ... a rep for MTA tells us a large portion of the money Tekashi's attorney offered up in court for his bail rightfully belongs to the company. MTA says it's already sent him $860k for deposits on upcoming shows in the U.S., Mexico and Germany. Presumably, he won't be able to perform those shows, so MTA wants that money back.
We're told MTA's working with its legal team to prevent 6ix9ine from using any of that dough for bail.
We broke the story ... Tekashi's been placed in general population at Brooklyn's Metropolitan Detention Center -- despite being a potential target for violence -- while he awaits his Wednesday's bail hearing.