WARSAW, Poland (AP) — A disciplinary court in Poland on Thursday lifted the immunity of a judge who fled the country to neighboring Belarus, an autocratic ally of Russia, paving the way for an international arrest warrant for him on espionage allegations.

Poland's prosecutors and special services launched an investigation this week after Belarus media reported that the judge, Tomasz Szmydt, arrived in the country and asked for protection. Politicians in Poland, which is a NATO and European Union country, vowed to take immediate steps to strip Szmydt of his immunity as a judge, remove him from his post and take actions to bring him to justice.

Szmydt was notorious in Poland for having engaged in a 2019 online smear campaign against other judges that was sponsored by the Justice Ministry under the previous right-wing government.

Justice Minister Adam Bodnar said stripping him of immunity allows for posting an international arrest warrant for Szmydt through Interpol. Even if Belarus ignores it, the warrant would restrict Szmydt's ability to travel.

According to Belarus state media, Szmydt told reporters in Minsk, the Belarusian capital, that he was forced to leave Poland because he did not agree with the new, pro-Western government.

Deputy justice minister in the new government, Arkadiusz Myrcha, said in parliament on Thursday that answers are needed about Szmydt's swift rise under the previous government and why he had access to sensitive information.

Speaking later in parliament, Prime Minister Donald Tusk accused the previously ruling populist Law and Justice party of ties to the intelligence services of Russia and Belarus, and said the scope of the alleged ties will be probed by a special parliamentary commission. Tusk said Szmydt's story was only a small part of those alleged ties.

Szmydt's defection came as a shock in Poland, which supports Ukraine in its war against Russia’s aggression and which has a history of distrust with Russia.

Tusk on Tuesday called for a special meeting of the secret services to discuss alleged Russian and Belarusian infiltration after Szmydt’s defection. He later said the defection was “treason” and vowed swift legal action in response.