Brian A. Larsen claims his pitch for "The Swissman" contained key elements found in the show starring Liev Schreiber as a Hollywood fixer.

A writer is suing Showtime for allegedly stealing his concept for a TV show and using it for Ray Donovan.

Brian A. Larsen's lawsuit, filed Thursday in Los Angeles Superior Court, claims he pitched network executives a show called The Swissman in the fall of 2010 and winter of 2011. According to the suit, Larsen's pitch included multiple similarities to Ray Donovan, which stars Liev Schreiber as a Hollywood fixer.

Read the complaint here.

Larsen's suit says his concept centered on a "middle-aged protagonist who is a 'fixer' -- also known as a man who orchestrates the killing or otherwise violent disposing of people for hire." The protagonist would have a "tumultuous" relationship with his father, have a "troubled relationship" with a catholic priest and deal with a brother who is constantly getting himself into trouble.

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"The unmistakable central theme is whether a fixer has a moral obligation to do the right thing or if he is simply supposed to 'do his job,' " the suit reads.

Larsen's suit says he conceived of the concepts for the show in the fall of 2005, and worked on the script from 2006 to 2009, registering the concepts with the Writers Guild of America in September 2009. He then worked with the literary agency RWSG, and in 2010 began working with Universal Cable Productions to set up meetings with distributors and production companies to turn his script into a television show.

The suit says that in November 2010, Larsen pitched the idea to Showtime development executive Danielle Gelber, who allegedly told him she would "pitch like hell" to get Showtime to board the project. Several days later he had a meeting with more Showtime executives, but was soon told the network was not interested in pursuing the project.

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Ray Donovan is produced by The Mark Gordon Company, which developed the project as a feature film before pitching it as TV show. It debuted on Showtime in 2013.

Larsen is suing for breach of implied contract and breach of confidence. Among other things, he is seeking restitution and general damages at a trial by jury, as well as for the show to cease production. A second season of Ray Donovan is expected to air this year.

A Showtime rep said, "As Showtime has not been served with this lawsuit, we have no comment."