It’s arguably Led Zeppelin’s most recognizable and iconic song, and now the band is facing a lawsuit over where “Stairway to Heaven” came from. The band Spirit is claiming that Zeppelin’s famous tune is a rip off of Spirit’s 1968 song “Taurus.”

The Guardian is reporting that the trust for Randy California, Spirit’s late lead singer, is heading up the suit. But it’s not the first time the allegations have been made. In an interview before he died, California himself stated that Zeppelin had copied Spirit’s song. Calling the hit song “a rip-off,” California said, “[Led Zeppelin] made millions of bucks on it and never said thank you; never said, ‘Can we pay you some money for it?’” According to California’s trust, the band didn’t take action then because of financial limitations. California drowned in 1997 while trying to save his 12-year-old son from drowning in the ocean near Hawaii.

The members of Led Zeppelin were no strangers to Spirit. The bands toured together during 1968 and 1969, and often played the song “Taurus.” “Stairway to Heaven” was written later on, in 1970.

The buzz about the lawsuit comes just after Jimmy Page made some harsh comments about Robert Plant’s role in the band’s touring status, saying he was “fed up” with Plant playing games regarding a possible reunion tour for Led Zeppelin. Zeppelin is also getting ready to release a reissue of 1971’s IV, which happens to feature “Stairway to Heaven” as one of its tracks. California’s trust is planning to release a copyright infringement suit, hoping to get an injunction that would block the release of Led Zeppelin’s reissue. Copyright infringement suits are only good for three years after the release of material in the United States, but California’s trust could still sue for recent proceeds from “Stairway to Heaven.”

If you’re curious about the similarities between “Taurus” and “Stairway to Heaven,” have a listen below.