0359 GMT October 20, 2021
The former president of Spain's Catalonia region was due to appear in a court of appeal in the Sardinian city of Sassari later on Friday, according to Reuters.
Agostinangelo Marras, a lawyer for Puigdemont in Sardinia, told Italian news agency ANSA that the court would rule whether to confirm his arrest or release him, but would not decide at Friday's hearing whether he should be extradited.
Puigdemont's arrest is likely to stir emotions among his supporters, potentially complicating a new attempt by the Spanish government to hold talks with Catalonia's separatist government on the region's future.
Police cordoned off some streets in the Catalan capital Barcelona after a few hundred protesters gathered in front of the Italian consulate, waving Catalan separatist flags and chanting "Puigdemont is our president" and "Free Puigdemont".
Puigdemont, 58, has been living in self-imposed exile in Belgium since late 2017 after Spain accused him of helping to organise a 2017 independence referendum deemed illegal by Spanish courts.
He has served as a member of the European Parliament since 2019, but was detained by Italian border police at Alghero airport as he arrived in Sardinia from Brussels to attend a cultural event on Thursday evening.
"Mr Puigdemont must submit to the action of the courts, exactly like any other citizen," Spanish Prime Minister Pedro Sanchez's office said in a statement.
If extradited, Puigdemont is likely to face the same Supreme Court trial that sentenced nine Catalan separatist leaders to lengthy prison terms in 2019 for their role in the 2017 attempt to break away from Spain.
The Spanish government pardoned them in June but said Puigdemont still had to face justice in Spain.
Puigdemont was subject to a European arrest warrant issued by Spain and the European Parliament stripped him of immunity in March.
In 2018, Puigdemont was arrested in Germany but avoided extradition. Belgium has refused all Spain's extradition requests to date and he travelled to Paris last week without apparent difficulties.