Ubisoft has reactivated the stolen game keys it revoked last month.

The company had deactivated thousands of keys for games including Far Cry 4 and Assassin's Creed: Unity after learning that they were purchased via Origin with a stolen credit card then resold via third-party websites.

“After further investigation into the matter of keys that were fraudulently purchased on EA's Origin store, we are reinstating keys for consumers who already had successfully activated and started playing the games,” a representative told GameInformer.

“Any remaining fraudulently obtained and resold keys have been deactivated.

“We are working with EA to prevent situations like this from happening again, and we will continue to deactivate keys that are found to be fraudulently obtained and resold,” the representative added.

“We strongly recommend that players purchase keys and downloadable games only from the Uplay shop or trusted retailers.”

The keys had been resold via merchants on Kinguin, an eBay-style key marketplace, and their deactivation had drawn the ire of gamers as well as Kinguin marketing head Bartłomiej Skarbiński.

"From the gamer point of view its like going out to the store, purchasing a copy of the game, taking it home and suddenly a knock-knock on the door with Ubisoft representative taking the copy away - not even asking you as a paying customer to return it," Skarbiński said at the time.