'Black Lives Matter' Leader Shaun King -- Shades of Rachel Dolezal ... Did He Dupe Oprah?

3:30 PM PT -- King is finally responding to the allegations ... with a Twitter rant, but he's playing it close to the vest. He says, "Out of LOVE for my family, I've never gone public with my racial story because it's hurtful, scandalous, and it's MY STORY."

He also claims the whole story is a right-wing "hit piece."

Rachel Dolezal is not alone, allegedly -- one of the leading Black Lives Matter activists might actually be a white guy ... who got a scholarship to a Black college from Oprah Winfrey!

35-year-old Shaun King has always claimed to be biracial -- Caucasian mom and an African-American dad -- but Breitbart says a 1995 police document identifies King's ethnicity as white.

The website also says it found what it believes to be a mug shot of King's dad ... and the guy in the pic is white.

It is possible the police report is a clerical error, and the mug shot is not actually King's father.

King himself hasn't responded to the report -- but we're guessing Oprah will have extreme interest in what he says. King has said he got a leadership scholarship from O to attend Morehouse College. The scholarship is designated for African-American students.