A staff member of the Ukrainian ombudsperson's office, Ihor Mazur, has been detained at the Polish border checkpoint Dorohusk, Ukrainian ombudsperson Lyudmyla Denisova has said on Facebook.
"The issue of placing our colleague into custody for the purpose of extradition to Russia will be decided in Chelm on Monday, 11 November," she said.
Ihor "Topolya" Mazur is a deputy head of the Ukrainian National Assembly-Ukrainian People's Self-Defence (UNA-UNSO). He fought in Chechnya against Russian government troops. Mazur also took part in the Ukrainian-Russian war in Donbas.
The UNA-UNSO said that he was detained on Russia's request over his participation in the Chechen war.
"The detention took place in response to the Russian Investigations Committee's request to Interpol to organise international search for Ihor, UNA-UNSO leaders and members of other political parties on charges of participating in the battles on Minutka Square in Chechnya. Ihor was traveling to Poland at the invitation of Deputy Marshal of the Polish Sejm Beata Mazurek," it said.
The party noted that "now, Polish law-enforcement officers are to submit a request to the Russian Federation to receive the documents of the case and a Polish court is to decide to extradite him or turn down Russia's request".
An ex-adviser to the Security Service of Ukraine (SBU) head, diplomat Markiyan Lubkivskyy said on Facebook that Ukrainian "diplomats are doing everything possible to free Ihor 'Topolya' Mazur".
Mazur spent three years in prison for participating in a clash with police under the Presidential Administration during the campaign "Ukraine without Kuchma" in March 2001.