Federal inmate Gary Cole is suing Taco Bell, claiming the fast food chain stole his idea for the hugely popular Doritos Locos Tacos.

Cole, who is finishing up a 25-year sentence for “delaying interstate commerce, conspiring to do so, and using and carrying a firearm in relation to a crime of violence” in a Colorado federal prison, claims in court papers that he had the idea for Dorito-flavored taco shells in 2006. Taco Bell released the Doritos Locos Tacos last year.

The federal inmate, currently being housed in the supermax federal prison in Florence, Colo., filed papers in Dallas federal court against Taco Bell alleging the company snatched up his idea, the Dallas Observer reported.

Cole gave the alternative weekly a copy of a 2006 notarized document he mailed to his attorney with a list of nine products the inmate claims he conceived from his cell in Florence. Among the products are “tacos [sic] shells of all flavors (made of Doritos,)” according to the Observer.

The list also includes hot sauce, alcohol, “health mix,” body oils and other products under a brand Cole called “Divas and Ballers.”

When the inmate learned of Taco Bell’s plans to roll out the Doritos Locos Tacos, Cole said he supposed Taco Bell somehow got a hold of the 2006 letter. The inmate tried to get the FBI on the case, as well as the IRS, telling the tax agency that "a check was made out to a person for a large amount by Taco Bell, Frito Lay and Pepsi Co. Inc. for an idea or invention that was submitted to them by theft and fraud," the Observer reported.

He wanted to know information on “"the person, the name, address, the amount of the check, how much taxes paid on the check” and called on Taco Bell to release documents related to their conception of the Doritos Locos Tacos.

After he didn’t hear back from Taco Bell, Cole filed his lawsuit in Dallas federal court. The federal inmate is representing himself in the case, but the court papers showed that he tried to get a Denver law firm to represent him, the Observer reported.

Cole didn’t send the newspaper the letter that he wrote to the law firm, but he did provide the weekly with the law firm’s response, which refers to Cole wanting to “put a knife” to someone.

“Thanks for your April 25th letter, which we received on May 3. By now you should have received the taco documents. Hopefully, the stress they caused will be relieved,” the law firm replied. “Do not ‘put a knife’ to the staff. That won't do you, or us, any good. I understand your frustration, but we're working on the retaliation issue and would ask that you leave it in our hands.”