In a statement posted on the organization's website, the OSCE's representative on freedom of the media, Miklos Haraszti, condemned the lack of transparency in the handling of the cases of Annakurban Amanklychev, Sapardurdy Khajiev, and RFE/RL Turkmen Service correspondent Ogulsapar Muradova.
The three were sentenced on August 25 to up to seven years in jail each on charges of illegally possessing ammunition.
No independent observers were allowed to attend the proceedings, which lasted just a few minutes.
Talking to RFE/RL's Turkmen Service today, Haraszti said he was particularly concerned by the fact that the defendants were reportedly held incommunicado before and during the trial.
"It is worrying that observers were not allowed to visit [the defendants], not even family members," he said. "That leaves open the question, for public opinions both in Turkmenistan and outside, [of] what did actually happen, what actually [were] the charges, and whether due defense was provided to them. These questions can be clarified only by [observing] the principles of a fair and open trial and access to the defendants by public questioners, families, and defense lawyers."
The Paris-based Reporters Without Borders (RSF) and the New York-based Committee to Protect Journalists (CPJ) both expressed outrage at the sentences.
France today called upon Turkmen authorities to respect their commitments with regard to human rights and press freedom. It said it would consult with other European Union countries on what "further steps" to take.
RFE/RL's acting president, Jeff Trimble, has condemned the trial as "a mockery of justice."