MOSCOW (Reuters) - Valentina Chupik, a human rights lawyer who operates a hotline for migrants in Russia, said she has been detained at a Moscow airport after the country's security service revoked her refugee status.

       "I am at Sheremetyevo airport, in a special detention centre... I am afraid I will be deported to Uzbekistan," Chupik told Reuters on Saturday, adding that her deportation was expected within 24 hours.

       Russia's FSB security service has barred Chupik, an Uzbekistan citizen who has held refugee status since 2009, from entry to Russia for 30 years, the Novaya Gazeta newspaper said, citing a document provided by Chupik.

       The FSB did not reply to a request by Reuters for comment.

       Chupik's organisation, Tong Jahoni, provides free legal support to migrants in case of illegal non-payment of wages, deportation or detention.

       Millions of economic migrants, many from poor Central Asian republics whose economies rely on them sending home some of their salaries, work in Russia in the grey economy, where they can be exploited or cheated by employers.

       (Reporting by Polina Devitt; Editing by Mike Harrison)