Polish police on Friday detained exiled Chechen leader Akhmed Zakayev, who is wanted in Russia on terrorism charges, but later released him pending an extradition hearing, dpa reported.
The Warsaw district court rejected a request by prosecutors to place Zakayev under temporary arrest for 40 days. He had been arrested earlier Friday by Polish police on an international warrant issued by Russia through Interpol.
"It is a victory for the free world over the fictious allegations of Russia," Zakayev's aide, Adam Borowski, said.
Zakayev had arrived in Poland on Thursday to attend a two-day World Chechen Congress in Pultusk, in central Poland.
Police took Zakayev to the prosecutor's office Friday. Borowski said the Chechen leader had been en route to voluntarily turn himself over before he was picked up.
Zakayev told journalists that he believed Poland was a democratic country as he arrived at the prosecutors' office.
Russian prosecutors have asked Poland to extradite Zakayev, who has been living in Britain since 2002.
Polish prosecutors had said Wednesday that police would detain Zakayev if he arrived in Poland, in accordance with an international arrest warrant issued by Russia through Interpol.
The evidence against Zakayev was "very serious," and gave Poland "every reason" to hand the suspect over to Russia, said Konstantin Kosachev, chairman of the Russian parliament's foreign affairs committee.
Polish Prime Minister Donald Tusk has said that Poland had to honour the international arrest warrant, but that courts would decide whether to extradite the separatist leader to Russia.
"We will decide on this matter in accordance with our sense of Polish interests, decency and justice. And not to fulfil anybody's expectations," Tusk told Polish Radio on Friday.
Zakayev's detention came amid a shift in Polish-Russian relations.
Diplomacy was strained between Moscow and Warsaw after Poland this year deployed US missiles near the Russian border.
But relations warmed when Russia showed willingness to cooperate in a probe after a plane crash in Russia in April that killed Polish President Lech Kaczynski and 95 others.
Borowski said Zakayev did not want to "hide" in Poland and had agreed to report himself to prosecutors on Friday morning. Borowski said he did not believe Poland would extradite Zakayev, but that he was afraid they might do so "for the good of Polish-Russian relations."
Russian Deputy Prime Minister Sergei Ivanov told Russian media Friday that Zakayev's detention was a "positive moment" that showed relations between Moscow and Warsaw had eased.
Zakayev is the prime minister of the unrecognized separatist Chechen Republic of Ichkeria. He is a former deputy prime minister and former spokesman for President Aslan Maskhadov, who was killed in 2005 during fighting with Russia.
Zakayev is a veteran of two Chechen wars fought since 1994, and is now considered a moderate in the separatist movement in the Caucasus.
Zakayev was detained in 2002 in Denmark, but later released after officials ruled there was not enough evidence for extradition to Russia.
Zakayev was later detained in Britain and granted political asylum in 2003 after British courts there rejected Russia's extradition request.