A copyright and fraud complaint alleges the credited writer reached out to other composers and then passed off the work as his own.

Warner Bros. is now in court over allegations that the studio failed the devilish details before using the main title theme music to the Fox series Lucifer.

In California federal court, Robert Marderosian and Aron Marderosian (known as the "Mardos") say they were approached in October 2015 by Marco Beltrami, an Oscar-nominated composer (The Hurt Locker, 3:10 to Yuma).

"When Beltrami approached the Mardos, he was desperate," states the complaint. "Beltrami was not able to capture the essence of what Warner Bros. and NS Pictures were looking for in the main title theme for the Series, and each of the musical works previously composed and submitted by Beltrami to Warner Bros. and NS Pictures had been rejected."

The plaintiffs say they stepped in to write and record a music theme provided they would be credited as co-writers and that ownership of the music publishing would be split. Warner Bros. allegedly was "ecstastic" with the results.

"However, Plaintiffs are informed and believe and based thereon allege that Beltrami failed to inform Warner Bros. or NS Pictures of his agreement with Plaintiffs," the complaint continues. "Instead, Plaintiffs are informed and believe and based thereon allege that Beltrami passed off the Master and Composition as his own original work and fraudulently represented and warranted to NS Pictures and Warner Bros. that Beltrami owned and controlled all right, title and interest therein."

The Mardos say they put Warner Bros. on notice, but that the Lucifer theme was used anyway. They allege that Mardos agreed to split the writers' portion of music publishing in the six-second theme for cue sheet purposes, but not the full composition. They also say an agreement was made over credits, but that Beltrami "in fact had no subjective intention to fulfill it."

Lucifer is now in its second season, and the complaint says that Warner Bros. has registered the publisher's share of the composition with the performance rights organization BMI.

Warner Bros. is now being sued for copyright infringement while Beltrami and his loan-out company are being targeted for fraud. The plaintiffs are represented by Brian Wolf at Lavely & Singer. Here's the full complaint.

We've reached out to Beltrami's representative for a response and will provide it here if anything comes. Warner Bros. declined comment.