Darez Diggs -- the brother of NFL superstars Stefon Diggs and Trevon Diggs -- has just been sued over his alleged role in a violent elevator attack last year.
Cristopher Griffith filed the lawsuit against the former XFL player on Tuesday ... alleging Darez and several others beat him up as he was getting off an elevator at his Downtown Los Angeles apartment building on May 29.
Griffith said in the suit the attack left him with pain, suffering and emotional distress. He's also suing Darez for $100,000 in jewelry and other property he claims he had on his person during the incident.
Griffith is suing the owner of the apartment complex for unspecified damages as well.
The alleged altercation, of course, was captured on video obtained by TMZ Sports. The footage appears to show Darez standing by as two other men kick and punch Griffith inside the lift.
The clip also appears to show the men taking Griffith's jewelry, before leaving the area.
A spokesperson for the LAPD told us on Wednesday authorities are still investigating the matter ... and no arrests have been made.
For Darez's part, he's never commented publicly on the situation ... though just weeks after it all happened, he was seen in good spirits while working out at Stefon's youth football camp at the Univ. of Maryland.