Fresh off his very first Oscar win, Spike Lee's got a new legal headache ... over one of his movies from the '90s and a Prince song.
Longtime friends Prince and Spike teamed up for his 1996 flick, "Girl 6" ... with Prince writing and performing the title song for the soundtrack. According to a lawsuit filed by James Brandon, that track jacked one of his songs.
In docs, obtained by TMZ, Brandon says he was in a group called GOMAB and met with Spike's uncle, Clarence Lee. Brandon and his group had recorded a song called "Phone Sex" in 1993, and Clarence offered to get it to Spike ... for possible use in one of his movies.
Lo and behold, "Girl 6" happens to be all about a phone sex operator -- played beautifully, BTW, by Theresa Randle.
Anyway, the movie came out and Brandon says he immediately heard similarities between his song and Prince's -- such as the trumpet arrangement and at least part of the vocal arrangement.
In his suit, Brandon says his song used the hook, "Phone sex" ... and Prince's song had the same melody, but just changed the lyrics to "Girls six."
Brandon's suing the Prince estate and Spike for all profits they made off the song.
We've reached out to Spike's camp and the estate to get their response.