Amnesty International and a British activist have been banned from visiting Azerbaijan ahead of the controversial European Games Baku 2015.
The organisation was forced to cancel a scheduled visit to launch a briefing entitled "Azerbaijan: the Repression Games. The voices you won't hear at the first European Games".
Authorities told Amnesty that the country "was not in a position to to welcome the Amnesty mission to Baku at the present time".
"It is deeply ironic that the launch of a briefing outlining how critical voices in the country have been systematically silenced ahead of the European Games cannot be held. But rather than bury this message, the actions of the authorities have only highlighted their desperate attempts to create a criticism-free zone around the Games," said Denis Krivosheev, Amnesty International's Deputy Director for Europe and Central Asia.
"Far from advancing the goals of press freedom and human dignity enshrined in the Olympic Charter, the legacy of these games will be to further encourage repressive authorities around the world to view major international sporting events as a ticket to international prestige and respectability."
The development came after Emma Hughes, a campaigner with the British rights group Platform London, was detained while going through security checks at Baku's Heidar Aliyev international airport. The activist was told she had been blacklisted by the Azerbaijani government.
Human rights groups accuse Baku of exploiting the European Games to whitewash the country's human rights abuses under the authoritarian rule of President Ilham Aliyev.
The gas-and-oil-rich Azerbaijan capital will host 6,000 athletes from 50 countries to compete in 20 sports.
Amnesty International has received an increasing number of reports of arrests, detention and harassment of human rights activists, the political opposition and government critics in Azerbaijan ahead of the Baku 2015 event. Other organisations such as Index on Censorship are documenting similar concerns.
Azerbaijani journalists, human rights defenders and opposition members are being harassed, arrested, jailed, attacked and tortured on a daily basis ahead of the Games. Amnesty lists at least 20 prisoners of conscience in the country.
Among the journalists being persecuted in the country is Khadija Ismayilova, a prominent journalist with the US government-funded Radio Free Europe/Radio Liberty who had investigated claims of corruption within the ruling family businesses.
The 38-year-old journalist stands accused of driving a former colleague at the radio station to a suicide attempt and she could face up to 12 years in prison if found guilty.