Christian musicians sue Katy Perry over "Dark Horse" (Twitter/@CosmopolitanUK).

The group - Grammy-winning rapper LeCrae Moore, Grammy-nominated rapper Flame (also known as Marcus Gray), Chike Ojukwu, and Emanuel Lambert - have sued Perry and Capitol records in St. Louis federal court.

The 29-year-old, who launched her career as a Christian singer herself, is accused of ripping off the Christian rap song and then "exploited and profited" from its use.

The musicians' lawsuit claims their song has been "irreparably tarnished by its association with the witchcraft, paganism, black magic and Illuminati imagery" in Perry's song and its music video.

Read more on the controversy here. 

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