Oscar nominee Eric Roberts has joined the cast of writer-director Tom Six's franchise finale The Human Centipede III (Final Sequence).

Producer Ilona Six also confirmed that Tommy Lister, Robert LaSardo, and Bree Olson have joined the cast. No character details were released.

RELATED: Dieter Laser Dies, The Human Centipede Star Was 78

We reported in January that The Human Centipede (First Sequence) star Dieter Laser is joining The Human Centipede II (Full Sequence) star Laurence R. Harvey as a villainous duo, with writer-director Tom Six starring as well. Our report from January also revealed that a "big American celebrity" will make a cameo appearance in this sequel, which will feature a 500-person centipede.

In related news, a casting breakdown offers a few spoilers about where this massive centipede will take place. There are spoilers below, so read on at your own risk.

"PRISON INMATES (NON UNION) / Non-Union / Human Centipede III / Background / Male / All Ethnicities / 18-65

Human Centipede III, a horror film, is looking for gentlemen of all ages, sizes, and ethnicities to play PRISON INMATES starting Thursday - May 16 in Los Angeles. These prisoners will work up to 13 days between May 16 and June 6. We will be shooting at a number of actual prisons in the LA area. Applicants can be expected to engage in regular prisoner activities like rioting, screaming, and fighting. However, this is a Human Centipede movie. THERE WILL BE SOME SCENES TOWARDS THE END OF THE SHOOT REQUIRING PRISONERS TO BE PART OF THE HUMAN CENTIPEDE. Actors will be fully clothed, but will be asked to pose on their hands and knees rear end to mouth. Please do not apply if uncomfortable with this process. Show is non union. Rate is 64.00/8 + Mileage on some far away prison shoot days."

Production is currently under way in California, although it is not known when this sequel may be released. Eric Roberts most recently starred in Uwe Boll's Assault on Wall Street, and will next be seen in Abstraction and Lovelace.