Despite heavyweight director Steven Spielberg's strong efforts to keep the latest "Indiana Jones" movie out of anyone's sight until May 18, a number of reviews have already surfaced online.

Together with executive producer George Lucas and Paramount Pictures, Spielberg is making great efforts to keep "Indiana Jones and the Kingdom of the Crystal Skull" at bay from the critics and the audience until the screening time. This is partly to create anticipation from the audience, who had been waiting for the fourth installment of the highly successful franchise.

The film is yet to make its debut at the Cannes Film Festival on May 18; however, there are already reviews that appeared Thursday.

Aintitcoolnews.com has published a review and film details from a poster identified only as "ShogunMaster" saying "This is the Indiana Movie that you were dreading."

Two other less harsh, albeit also less flattering, reviews have also been published on the site.

"ShogunMaster" claims he is a theater executive who saw the film at an exhibitor's screening last week. He insisted on anonymity to avoid retaliation from the studio.

That must have defeated Spielberg's cause. He has been really careful so far to avoid leakages as such. Last year, the producers filed a lawsuit against a bit player who had publicly discussed the film's plot.

NY Times says that Spielberg has kept an eagle eye on every aspect of the film's marketing campaign. According to the director's longtime publicist Marvin Levy, who himself has not seen the film yet, he watched and supervised everything on "every TV spot, every line in every ad, every advertising concept" to avoid the dreaded leakage.

"Indiana Jones and the Kingdom of the Crystal Skull" stars Harrison Ford, who reprises his role as the title character, Shia LaBeouf, and Cate Blanchett. It will be shown to the public on May 22.