U.S. animation studios may have unknowingly had work on their projects outsourced to illustrators and graphic designers in North Korea, according to a report. Drawings for an upcoming season of Invincible, an Amazon Prime Video show, and other work that appears to be for the forthcoming Max series Iyanu: Child of Wonder were found in a trove of documents found by American researchers on a computer server located in North Korea, according to CNN. The network says there’s no evidence suggesting the studios knew their proprietary work was on the server, with experts who analyzed the files claiming that the sketches appear to be work that was unknowingly outsourced to North Koreans. Skybound Entertainment, which produces Invincible, said it doesn’t contract with Chinese or North Korean countries and said it is investigating the matter. A source told CNN that Lion Forge Entertainment, which produces Iyanu, had contracted with a South Korean animation studio, but it then cut ties with the studio in January after discovering it had further outsourced the Iyanu work.