Fat Joe — Notorious B.I.G. Mystery Revealed … He Banged Anthony Mason's GF

It’s one of the biggest mysteries in the history of hip-hop … Which Knicks player was robbed by the Notorious B.I.G. after he walked in on Biggie banging his GF?

According to Fat Joe it was Anthony Mason … and Joe made this BOMBSHELL revelation while talking with the guys on ESPN’s “Highly Questionable” Monday morning.

The song is legendary … called “I Got A Story To Tell,” it chronicles Biggie’s one night stand with a Knicks player’s GF that almost ended up deadly when the unnamed player arrived home early.

Biggie maintained the story was true … but for years we didn’t know who it was until Joe spilled the beans earlier today.

Check out the clip …