Catalonia's former leader Carles Puigdemont talks to the media as he leaves the prison in Neumuenster. Picture: Fabian Bimmer/Reuters

Berlin - Supporters of former Catalonian president Carles Puigdemont - a key advocate for the region's independence from Spain - lined up in the German capital Saturday amid a throng of journalists awaiting a statement from the recently incarcerated leader.

Puigdemont is expected to speak at noon (1000 GMT) at Aquarium, a former pet store that is now a refugee advocacy centre in a primarily residential part of Berlin's Kreuzberg district.

Some supporters carried a sign reading "Llibertat Presos Politics" (Freedom for political prisoners). It displayed images of Jordi Sanchez and Jordi Cuixart, two other Catalan independence leaders who were jailed in Spain last year amid efforts to create a Catalonian nation.

Another woman brought yellow flowers to signify the Catalonian spring.

Puigdemont, 55, was detained March 25 on a European arrest warrant issued by Madrid, which accuses him of rebellion and misuse of public funds for organizing an independence referendum in Catalonia in October. He was travelling by car through Germany at the time, from Finland to Belgium, where he has lived since fleeing Spanish justice last year.

Activists put up banners with the photos of jailed leaders of Catalan pro-independence movements before Catalonia's former leader Carles Puigdemont addresses a news conference in Berlin. Picture: Hannibal Hanschke/Reuters

A German court ruled Thursday that extradition was not permissible on the basis of the rebellion charge, because the comparable German charge of treason stipulates that the defendant must have committed violence.

But Puigdemont could still be extradited on the misuse of public funds charge, which relates to questions about the legality of the referendum.

A demonstration against his still-possible extradition to Spain was also planned in the northern town of Neumuenster, where Puigdemont had been held following his arrest on March 25.

A protestor holds a flag of Schleswig Holstein and a placard reading "The freedom of the Catalans also counts in Schleswig Holstein" in front of the prison in Neumuenster. Picture: Fabian Bimmer/Reuters

The Spanish Supreme Court is also considering appealing to the European Court of Justice in Luxembourg for a preliminary ruling on the case.

In the meantime, Puigdemont, who had to pay 75,000 euros (91,700 dollars) in bail, must remain in Germany, report weekly to police and inform authorities of any change in his address.

German Justice Minister Katarina Barley welcomed Thursday's court ruling, telling the Sueddeutsche Zeitung newspaper it was "absolutely right."

Spain would now have to prove that Puigdemont was guilty of misusing public funds, she said, adding "That won't be easy."