Independent lawyer and rights campaigner Surat Ikramov told RFE/RL's Uzbek Service the verdict was reached behind closed doors on September 8.
Ikramov said the defendant was denied any legal counsel and that only two witnesses for the prosecution attended the final phase of the court hearings.
The 66-year-old poet Hasan was charged with insulting Uzbek President Islam Karimov and threatening public security.
His trial started on July 31. Uzbek authorities say 187 people -- including many security officers -- died during the May 2005 antigovernment uprising in Andijon. But rights groups say troops killed hundreds of unarmed civilians.
The song Hasan wrote after the events refers to the eastern Uzbek city being "drowned in blood" and victims "falling like mullberries."
(RFE/RL's Uzbek Service)