Katy Perry loses to Christian rapper Flame in court as Jury finds that her 2013 hit, Dark Horse, was copied from his 2009 song

Katy Perry has lost to Christian rapper Flame in a copyright infringement trial.

A federal jury in Los Angeles on Monday ruled that Katy Perry's 2013 song Dark Horse violated copyright infringement law in its similarity to the 2009 song Joyful Noise from Flame, a Christian rapper.

Flame, whose real name is Marcus Gray, filed the suit in 2014 with two other authors of the song. He claimed in the suit that Dark Horse incorporated beats and instrumentals that paralleled those in Joyful Noise.

But Katy Perry's lawyers told the court that the parts of the song Flame and his team cited were musical basics, and that the trickle-down effect of a loss in the suit would have a negative impact on the industry.

Perry's lawyer Christine Lepera told the court last week: "They're trying to own basic building blocks of music, the alphabet of music that should be available to everyone."

Katy Perry and Dark Horse co-writer Dr. Luke both took the stand at the week-long trial, claiming they never heard of Flame and were not listeners of Christian music.

But Flame's legal team argued their client had significant exposure prior to the release of Dark Horse in 2013, as Joyful Noise had amassed millions of plays on Spotify and YouTube; and the album it was included on, Our World Redeemed, received a Grammy nomination for Best Rock Or Rap Gospel Album.

The trial ended in favour of Flame. The next step in the legal process will enter the penalty phase, in which the nine-person jury will determine the award for the copyright infringement violation, according to the AP.