Greece begins espionage trials against 24 servants.

More than two dozen aid workers will go on trial Thursday for their role in bringing migrants to Greece between 2016 and 2018.

Human rights groups condemned the trial as politically motivated, and Amnesty International described the allegations as “ridiculous”. Lesbos, the island at the center of the migration crisis, will host the process. Among the 24 defendants, 17 of whom are foreigners, is Syrian refugee Sarah Mardini, sister of Olympic swimmer Yusra Mardini. The brothers came to international attention in 2015 after bringing their refugee boat to safety after an engine failure.

Mardini was denied entry to Greece to defend himself and he had to follow procedures from Germany, where he was granted asylum.

Prosecutors allege that humanitarian workers linked to search and rescue teams monitored Greek coast guard radio channels. And used vehicles with fake military plates to enter restricted areas of Lesbos.

Some are still under investigation for other crimes, including human trafficking, and face up to 25 years in prison if convicted. “I was charged with a crime allegedly committed a year before I arrived on the island,” he added. Nils Muiznieks, director of Amnesty International’s European regional office, said in a statement. “The allegations you are facing are a joke and should not be brought to justice.”

“This iconic case shows how far the Greek authorities will go to prevent people from helping refugees and migrants. “The suspension of rescue services does not prevent people from making dangerous journeys; it just makes this trip more dangerous,” he added.

The trial comes as Greece’s conservative government. Led by Kyriakos Mitsotakis, is calling on human rights groups to limit the number of people entering the country.

Last year he introduced tougher rules for dozens of international humanitarian organizations. Which critics say makes work in the country difficult.