Bungie's upcoming game 'Marathon' has been accused of using plagiarized artwork in its alpha version.Artist Fern Hook accused Bungie of using textures similar to her original artwork without permission or attribution.Bungie admitted that a former artist included the stolen artwork in the game's textures without the team's knowledge.The company is reviewing its in-game assets and has reached out to Hook to discuss the issue ahead of the game's scheduled launch on September 23.