Attorneys for Thicke and the song's producer and co-writer, Pharrell Williams, filed a lawsuit in Los Angeles on Thursday asking a judge to determine their song does not copy songs composed by Marvin Gaye and George Clinton.
The suit states that representatives of the owners of copyrights to Gaye's song "Got to Give It Up" and Clinton's song "Sexy Ways" have warned Thicke and Williams that they have used elements of the songs in "Blurred Lines."
A representative for one of the defendants, Gaye's son Marvin Gaye III, didn't immediately reply to an email seeking comment.
"Blurred Lines" has been No. 1 on Billboard's Hot 100 chart for 10 weeks. It has sold 4.6 million tracks.