Amnesty International says two of its delegates have been detained when trying to enter Azerbaijan and then expelled from the country.
The London-based group said the two Georgian nationals were deported from the country by immigration officials upon their arrival at the airport in Baku on October 7.
Azerbaijan has come under growing criticism for a deterioration of the situation of human rights defenders and a crackdown on opposition.
Amnesty said the deportation of its staff "adds to a sad litany of journalists and human rights defenders being targeted, detained, and jailed simply for carrying out their work."
"There is no let-up in the government's repressive campaign to stifle all criticism and dissent," the advocacy group added.