Richard Morrill, who previously served as the singer's hairdresser, claims Stefani's tune, which she co-wrote with Williams and released in 2014, features some strikingly similar lyrics to a track he played her during a style appointment back in 1998.

The original song, titled Who's Got My Lighter?, was by his former group L.A.P.D. and Morrill is now reportedly seeking a percentage of the $25 million (£20.5 million) profit from the single, reports TMZ.com.