UPDATE: Nintendo has said that it is aware of the Wiikey group's attempts to hack Wii U security but believes the console's systems that block pirated games currently remain secure.
"Nintendo is aware that a hacking group claims to have compromised Wii U security," a spokesperson told Eurogamer. "However, we have no reports of illegal Wii U games nor unauthorized applications playable on the system while in Wii U mode.
"Nintendo continuously monitors all threats to its products' security and will use technology and will take the necessary legal steps to prevent the facilitation of piracy."
ORIGINAL STORY: The group responsible for the first Wii mod chip has claimed to have hacked the Wii U so it can play copied games.
"Yes, its real," reads an announcement on the Wiikey website. "We have now completely reversed the WiiU drive authentification, disk encryption, file system, and everything else needed for this next generation K3y. Stay tuned for updates!"
The WiikeU, as it's called, is described as the first optical drive emulator to enable users to play Wii U games from any USB media.
The group claims it's compatible with all Wii U models from all regions. However, it is important to note that the group is yet to publish evidence to back up its claim. And it appears WiikeU does not enable homebrew, region-free gaming or let anyone cheat in a game.
However, if WiikeU is the real deal, it's bad news for Nintendo, which battled against piracy throughout the Wii's lifecycle.
Digital Foundry's Richard Leadbetter said Nintendo is capable of combating the WiikeU with a new firmware update - and will be keen to do so as soon as possible.
"This looks like a variation on the optical drive emulators that appeared first on Xbox 360 - where the drive firmware was easily decrypted - and then latterly on PS3, which was much more of an effort to reverse-engineer," Leadbetter said.
"The fact that the comms traffic between the Wii U and the drive has been hacked so quickly is a major concern for Nintendo.
"In theory, the firmware on the drive can be rewritten with a new, secured version via a Wii U system update and thus nullify the device, but the question is how the Wiikey team reverse-engineered the system in the first place. Unless Nintendo re-secures whatever exploit was used, the pirates could issue a system update for their own hardware and the piracy will continue with barely a pause."
Eurogamer has asked Nintendo for comment.