Liam Neeson Says He Wanted to Kill 'Black Bastard' After Friend Was Raped

Liam Neeson is copping to going on the hunt for revenge decades ago against some "black bastard" ... after a close friend was raped by a black man -- and says the experience taught him a valuable lesson.

The actor says he walked the streets for days with a cosh -- a baton-like weapon -- as he looked for an opportunity to kill a random black man. We're told the incident happened more than 40 years ago. Neeson opened up about it for the first time while talking to The Independent about his new movie, "Cold Pursuit."

He said a female friend had been raped, and although she didn't know her attacker's identity, she knew he was black. Check out the clip ... Liam says he walked outside bars hoping to be approached by a black man so he could "kill him" as revenge for his friend's rape.

Neeson makes it clear nothing ever happened, and says he learned from his "awful" and "horrible" behavior ... revenge isn't the answer.