RSF said in a statement that "the haste with which the [Uzbek] authorities have acted is very suspect given their readiness to brand all government opponents and civil society activists as extremists."
Khamidov, one of the most famous sports reporters in Uzbekistan, was arrested at his Tashkent home on January 21. Police also searched his apartment and confiscated his computer, several books, and CDs.
Khamidov was charged with "organization or active participation in an illegal religious group." If found guilty he could face up to five years in jail.
The RSF noted that the arrest of Khamidov, 35, who used to work for Uzbek television as a soccer commentator and also was a former radio show host, comes two weeks after five independent Uzbek journalists were summoned to the Tashkent prosecutor's office for questioning about their professional activities.
RSF said the Uzbek government "is pursuing its offensive without fear of any reaction from the international community."
Khamidov's lawyer, Alisher Zaynutdinov, told RFE/RL on January 25 that an appeal has been made in a Tashkent regional court regarding Khamidov's case, but he does not know when it will be considered.
Zaynutdinov said Khamidov has admitted that he took part in two events dedicated to the birth of a child in the Tashkent region where the Salafiya branch of Islam -- which is officially banned in Uzbekistan -- was discussed by some people.
As the founder of a religious newspaper, Khamidov said he is frequently invited to religious events.
Surat Ikramov, a Tashkent human rights activist, told RFE/RL that Khamidov was working for a state television channel and his commentary was always agreed on with authorities.
Khamidov gained great popularity while anchoring a series of radio programs called "Among People," and he founded a newspaper with a similar title in February 2007 that explained the role of Islam in people's lives.
The newspaper was closed in August 2007, reportedly due to a violation of the media law.