Prosecutors in Germany have confirmed a press report that investigators have listened in on phone calls of climate activists from the Letzte Generation ("Last Generation") group, sparking widespread outrage Sunday.
The wiretapping was ordered as part of an investigation over suspicions that members of the group were "forming or supporting a criminal organisation", a spokesman for the Munich public prosecution's office said.
The Last Generation, known for gluing themselves to roads to draw attention to the climate crisis, condemned the eavesdropping, calling it "absurd".
Conversations between members of the group and journalists making media enquiries were among the calls monitored, the prosecutors' spokesman said.
While the journalists themselves were not targeted, they "were affected by the measures due to calls made via the monitored telephone numbers," he said.
The Sueddeutsche newspaper first revealed the wiretapping on Saturday, reporting that the surveillance had begun last October. The surveillance included monitoring emails, voice mail accounts and logging the GPS data of mobile phones, the paper reported.
Reacting to the news, The Last Generation group wrote on Twitter: "We protest showing our names and faces, publish our plans, accept the legal consequences.
"Nevertheless, the Bavarian LKA (police) logged telephone calls, emails and movement profiles. Even our press phone was monitored. That is absurd!"
It was unclear whether the surveillance was still ongoing, the group added.
Lars Castellucci, an MP from Chancellor Olaf Scholz's ruling Social Democrats (SPD), said the wiretapping "raises questions about proportionality".
Dietmar Bartsch, parliamentary leader of the far-left Linke opposition party, called the surveillance "completely inappropriate".
As part of a criminal investigation, police raided the homes of several Last Generation activists in May and also seized two bank accounts.
The activists have nevertheless vowed to continue their protests.
The group, whose direct action has delayed flights and blocked road traffic, has divided public opinion with its tactics.
Earlier this month, Last Generation protesters spray-painted a private jet orange, several activists gluing themselves to the plane and the tarmac.