- Mohammed ibn al-Dheeb al-Ajami had been jailed since November 2011
- Footage of him reciting a poem critical of Gulf governments was uploaded online
- Amnesty International described the case as "a blight on Qatar's international reputation"
Mohammed ibn al-Dheeb al-Ajami, who had been jailed since November 2011, was released to his family Tuesday night after receiving a royal pardon, Xabier Celaya, an information officer for the body, told CNN.
Rights group Amnesty International, which also reported Ajami's release, described the case as "a blight on Qatar's international reputation."
"The release of Mohammed al-Ajami is long overdue good news," said James Lynch, deputy director of Amnesty International's Middle East and North Africa program.
"It is absurd that he had to spend more than four years behind bars, when his poetry was simply the peaceful expression of his conscientiously held beliefs."
Ajami's ordeal began after he recited a poem he had written, the "Jasmine Poem," to a group of people in his apartment in Cairo in August 2010.
Someone present covertly filmed his recitation of the poem, which was broadly critical of governments across the region, and uploaded it to YouTube, where it was widely circulated, Amnesty said in a statement.
The Qatari government charged him with "publicly inciting to overthrow the ruling system" and "insulting the emir," and he was sentenced to life in prison in November 2012
, before his sentence was reduced to 15 years on appeal the following year, Amnesty said. Ajami's trial had been marred by irregularities, the rights group said.
"We hope that the authorities will take the opportunity of this release to review Qatar's criminal justice system and ensure that such flagrant violations of the right to freedom of expression are not repeated. This case has been a blight on Qatar's international reputation," Lynch said.
Amnesty said the terms of Ajami's release were not yet clear.