Kelly claims he was put on suicide watch this week after he was sentenced to 30 years in prison, arguing his 8th Amendment rights are being violated because "he is not suicidal and expressly told MDC officials that he was not suicidal and had no thoughts of harming himself or others."
In the docs, he mentions Jeffrey Epstein associate Ghislaine Maxwell -- who was also placed on suicide watch -- saying the same thing has happened to him.
Kelly says he's been placed in a single cell without bed rails, no showers, no shaving, no toilet paper, being forced to eat meals with his hands, and being shut off from loved ones. Kelly also says it's ironic inmates on suicide watch don't even receive psychiatric care.
Kelly is suing for damages from emotional distress.
The Bureau of Prisons tells TMZ ... "The BOP is committed to ensuring the safety and security of all inmates in our population, our staff, and the public. Humane treatment of the men and women in our custody is a top priority."
We also reached out to MDC Brooklyn warden, Heriberto H. Tellez, who Kelly named in his suit ... so far no word back.