Alexander Morris is elaborating on his alleged hospital experience -- this just days after suing the facility ... and now, we're getting the full scope of what he claims happened.
We spoke to the Four Tops singer on "TMZ Live" Thursday ... and he claims he was sent for a psych exam at Michigan's Ascension Macomb-Oakland Hospital last April -- where he alleges that white staffers, doubting his fame, put him in a straitjacket.
Alexander says instead of receiving proper care at the hospital after falling ill over the Easter weekend, he was left in the hallway for 3 hours ... this was detailed in his lawsuit, BTW.
He goes on to claim that when he was finally seen by the doctors, they led him to a security guard who asked him to put his phone in his bag ... assuring him he'd get his belongings back after the psych evaluation.
He says he was initially thrown off, but says he believed they thought he was delusional for claiming to be part of the band. When he offered to show proof of his occupation, the man allegedly responded, "Nothing you have do I want to see, or do I need to see."
Morris claims that's when they took him out of his clothes and put him in a restraint gown, basically a straitjacket.
With some perseverance, AM claims he managed to show a female nurse a video of him singing with Four Tops at the Grammys. It was only then that she realized he'd been telling the truth ... that's Alex's version of events anyway.
During his 5 days in the hospital, he claims no real effort was made by hospital members to right the wrong. Instead, as a token of their apology, he alleges they handed him a $25 Meijer gift card.
Alexander is going after the hospital for $75K in damages.