The Doha Centre for Media Freedom said on Monday that it has sacked its Dutch director general, Jan Keulen, without giving a reason for his departure.
Keulen took up the post in 2011, two years after his predecessor Robert Menard resigned and complained that the organisation was "stifled" by authorities and lacked independence.
"Doha Centre for Media Freedom has announced the departure of its general director, Jan Keulen, who was relieved of his duties on 26 November," it said.
The statement said a replacement was being sought for Keulen, but did not provide any more details about the decision, which staff had been informed of on Sunday.
Keulen himself said he was unsure as to why he had been fired, as he confirmed his departure in a message posted on Facebook.
"I'm leaving Doha Centre for Media Freedom... Of course, there remain a lot of unanswered questions why I was sacked this way, but I'm sure we'll know more in the coming weeks and months," he wrote.
The Doha Centre for Media Freedom was created in 2007 by the Qatar Foundation chaired by Sheikha Moza bint Nasser al-Masnad -- the mother of Qatar's emir -- and global media watchdog Reporters Without Borders.
The Centre describes itself as "a non-profit organisation working for press freedom and quality journalism in Qatar, the Middle East and the world".
But in 2009, Menard had charged that "certain Qatari officials never wanted an independent Centre, one that was free to express its views without being limited by political or diplomatic considerations, one that was free to criticise Qatar itself".
On Monday the Centre stressed its "continued commitment to all its local and international partnerships in the field of media, the protection of journalists and press freedom".