News site Eurogamer suggested popular gamers on sites such as YouTube and Twitch, who may be less critical than journalists, were sent games early.
Bethesda says it sends journalists games to review one day before release.
Eurogamer's reviews editor Martin Robinson said: "What publishers do with their code is their prerogative."
The company has not yet responded to the BBC's request for comment.
Many games studios send their software to so-called influencers - people with big followings on social networks and video streaming sites - to play and review, before release to the general public.
Robinson suggested some publishers approached influencers rather than journalists, as they were less likely to be critical.
"Why should a publisher hand over its most prized asset to us well ahead of the rest of the world and risk us kicking its face off?" he wrote.
But he argued studios should have enough "faith" in their games that they make them available ahead of release for "honest critical analysis".
In a blog, Bethesda said it "valued" reviews in the media but wanted everyone - both players and journalists - to experience new games "at the same time".
But Mr Robinson said it was inconsistent and "anti-consumer" to send games to social media stars before professional reviewers.
"Bethesda claims it wants you to get the game the same time as everyone else - at the same time as announcing a pre-order bonus that lets people play a day early," he wrote, adding that its new game Skyrim Remastered had been "in the hands of many 'influencers' and has been for some time".
Earlier in 2016, Bethesda sent journalists a copy of its highly-anticipated title Doom one day before its general release.
Many reviews were sceptical about the quality of the game, but it became a commercial success, and Bethesda said it would continue its policy of sending media copies a day before release.
Video game publisher Bethesda has been criticised for letting gamers with big online followings review new software before gaming journalists.