Al Ajami, also known as Ibn al Dheeb, was sentenced to life behind bars on November 29th for a poem that supposedly incites the overthrow of Qatar's ruling
system and insults its emir.
"We are concerned by the fairness of his trial, including the right to counsel," Cecile Pouilly, a spokeswoman for the Office of the High Commissioner for Human Rights (OHCHR), told reporters in Geneva on Tuesday.
She pointed to a number of "procedural irregularities" and stressed that several sessions had been held behind closed doors.
In addition, she said, "the initial statement of the defendant was allegedly tampered with to wrongly incriminate him for reciting his poem in public."
The OHCHR also voiced concern that "al Ajami has apparently spent many months in solitary confinement and remains there despite a court order" to move him to a normal cell.
The UN rights agency will continue to monitor al Ajami's case closely, Pouilly said, pointing out that an appeal was scheduled for January 27th.
Amnesty International, which has described al Ajami's life sentence as "an outrageous betrayal of free speech," has said Qatar only officially took the poet to trial over a 2010 poem criticising the emir.
However, the organisation said Gulf-based activists believed his arrest in November 2011 was really due to a poem he wrote earlier that year hailing Tunisia's Arab Spring revolution.
That poem also criticized governments across the Gulf region, with its line: "We are all Tunisia in the face of the repressive elite," and activists have suggested al Ajami's harsh sentence could be seen as a warning against any Arab Spring-like ambitions in Qatar.