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OTRC: Christopher Meloni joins 'True Blood' cast as powerful vampire

Christopher Meloni appears in a promotional photo for 'Law & Order: SVU' season 12. (NBC)

Christopher Meloni has signed on for a "major role" on HBO's popular vampire series, "True Blood," the network confirmed on Tuesday.

Executive producer Alan Ball told TVLine that the former "Law & Order: Special Victims Unit" star will portray an "ancient, powerful vampire who holds the fate of Bill and Eric in his hands."

Meloni will be a series regular, beginning in season 5 on the drama. The 50-year-old actor previously appeared on the HBO prison drama "Oz," between 1998 and 2003.

Meloni announced he decided not to reprise his role as Detective Elliot Stabler on the 13th season of "Law & Order: SVU" in May.

"It is true," the actor's spokesperson said. "12 very happy years with the show. On to the next chapter."

Meloni has appeared opposite Mariska Hargitay, who plays Detective Olivia Benson on the popular NBC drama, for 12 seasons since the show began in 1999.

Meloni is currently filming his role as Colonel Hardy in the upcoming Superman reboot, "The Man of Steel," helmed by "300" director Zack Snyder.

The film will star Amy Adams as Lois Lane and "The Tudors" actor Henry Cavill as Clark Kent/Superman.

Diane Lane and Kevin Costner have also signed on to play Ma and Pa Kent.

"The Dark Knight" director, Christopher Nolan, is also a part of the "Superman" reboot. He and his "Batman Begins" and "The Dark Knight" writing partner, David S. Goyer, are penning the script for the new film. Nolan is also on board as a producer.

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