Fugitive Kazakh tycoon Mukhtar Ablyazov's brother-in-law, Syrym Shalabaev, has been detained in Vilnius.
Media in Lithuania quoted the chief of the Lithuanian Criminal Police Bureau, Rolandas Kiskis, as saying that Shalabaev was detained on July 28 and his possible arrest and extradition will be decided by a court.
Shalabaev is a brother of Alma Shalabaeva, who is the wife of former Kazakh banker and opposition figure Ablyazov.
Ablyazov is currently in French custody fighting a French court's ruling to extradite him to Russia.
Accused of embezzling some $5 billion when he was head of Kazakhstan's BTA bank, Ablyazov is wanted for embezzlement by Kazakhstan, Russia, and Ukraine.
Ablyazov says the charges against him are politically motivated.
Kazakh investigators say Shalabaev was involved in Ablyazov's alleged illegal financial activities. In 2011, London's High Court sentenced Shalabaev in absentia to 18 months in jail for contempt of court.
Ablyazov's wife, Alma Shalabaeva, and their daughter were granted refugee status in Italy last year.
Based on reporting by Delfi.lt and Interfax