By Agence France-Presse
"The Qatar News Agency website has been hacked by an unknown entity," reported the Government Communications Office in a statement.
"A false statement attributed to His Highness has been published."
It added that an investigation would be launched into the security breach.
The statement attributed to the emir focused on sensitive regional political issues with other nations in the region, including Iran and Israel, and also Doha's relationship with new US President Donald Trump.
The "false statement" was reported by broadcasters in the United Arab Emirates and caused a stir on social media in the Gulf, before Doha scrambled to deny the claims.
The communications office added that the "State of Qatar will hold all those" who committed the breach accountable.