Richie Incognito says Jonathan Martin contemplated suicide back in May because he wasn't playing well ... and Richie just told the world on Twitter.
After weeks of silence, Incognito just WENT OFF on Martin ... saying "the truth will bury you and your entire camp."
But then Richie dropped the bombshell ... "FACT: Jonathan Martin told me he thought about taking his own life in MAY 2013 b/c he wasn't playing well. Told me he felt worthless."
The timing of Incognito's rant is interesting ... considering the man the Miami Dolphins appointed to investigate the alleged "bullying" situation is expected to release his report in the very near future.
We've reached out to Martin's camp for comment -- so far, no word back.