Earlier on Wednesday, word began to spread on forums that any user with a valid Battle.Net account could download, install and play the Diablo III private beta.
Users who joined the beta this way began to notice menus referring to the game as the 'Starter Edition', with occasional prompts to purchase the full version of the game.
Shortly after users began discussing the 'Starter Edition' on forums, Blizzard took the beta's servers offline stating it was working " to resolve an issue." The beta servers have since returned, with no more 'Starter Edition' prompts.
Blizzard has previously released Starter Editions for World of Warcraft and Starcraft II after release. These provided early game levels and features for free, with prompts to purchase the full version of the game.
Today's leak indicates that Blizzard plans a similar free-to-play version for Diablo III.
Users who saw the 'Starter Edition' prompts during the beta today say that all five of the game's classes were available.
The Diablo III beta will officially close on May 1, prior to the game's release on May 15.
Blizzard is also offering Diablo III free to users who sign up for the new World of Warcraft annual pass, a yearly subscription to the popular MMO.
Watch Diablo III's opening cinematic below: