The British star is revered for his caricature of a Kazakhstani journalist, and hosted this year's (05) MTV Europe Music Awards (EMAs) as the comic creation.
But the Kazakhstan government are appalled by Cohen's portrayal of the central Asian nation as a country of drunken racists, sexists and Stalinists, and have now closed down Borat.kz.
President of the Association Of Kazakh IT Companies, NURLAN ISIN, says, "We've done this so he can't badmouth Kazakhstan under the .kz domain name. He can go and do whatever he wants at other domains."
Cohen, who edits the site in character, previously wrote: "I'd like to state I have no connection with Mr Cohen and fully support my government's position to sue this Jew.
"Since 2003... Kazakhstan is as civilized as any other country in the world.
"Women can now travel on inside of bus, homosexuals no longer have to wear blue hat and age of consent has been raised to eight years old."
Cohen is currently working on feature length film BORAT: THE MOVIE.