Bullshit, Bullshit, Bullshit. If a Bench press sounds unbelievable, don't believe it because it's B.S.
And Valuev definitely can't bench press anything close to 900lbs, let alone 500lbs or even 300lbs. My guess would be that Nikolai Valuev can bench press about 250lbs on a good day. Despite his stature, he simply isn't that strong.