Shortly afterwards Puigdemont was charged with rebellion, sedition and misuse of public funds, which respectively carry maximum sentences of 30, 15 and six years.
The worldwide arrest warrant for Puigdemont was reactivated Friday when he was visiting Finland.
The move to break away led Madrid to oust the region's government, after which Puigdemont fled the country.
Protesters wave Spanish and Catalan Senyera flags during a pro-unity demonstration in Barcelona on October 29, 2017.
A Neumuenster court stated that all formal requirements to arrest Puigdemont had been met by the European arrest warrant issued in Spain.
Mr Puigdemont was remanded in custody in Germany last night, before an extradition decision expected within 60 days, as new details came to light about his arrest on Sunday.
Spain's central government should not "sing victory because it is not the end of separatism, far from it", she added.
Catalan police decked out in riot gear shoved and hit demonstrators with batons to keep the crowd from advancing on the office of the Spanish government's representative in Barcelona, the capital of the wealthy northeastern region.
Catalan parliament speaker Roger Torrent appealed for calm in an address broadcast on regional television.
Ireland to expel Russian diplomat over United Kingdom nerve agent attack
The officials weren't authorized to be identified by name and spoke on condition of anonymity. He did not bring up the poisoning attack in his phone call with Putin.
"I have no doubt that Catalan society will act as it always has, with non-violence", he said.
Following the ruling, his case was expected to be submitted to Higher Regional Court in Schleswig, which is responsible for the worldwide extradition matters.
He travelled to Finland last week to speak at an event but left on Saturday to return to Belgium, only to be seized by German police after crossing the border from Denmark in an operation involving Spanish intelligence agents.
That vote had been swiftly followed by the Catalan parliament's declaration of independence on October 27.
In Scotland, where authorities have received an extradition request for Clara Ponsati, one of the cabinet members in exile, the SNP said it would complain to the Council of Europe over the cases.
More than 50,000 demonstrators subsequently clashed with Spanish police in Barcelona, demanding that Berlin release Puigdemont and refuse to extradite him.
The Spanish government called new regional elections in December, in which secessionist parties won again, but have since been unable to form a new government, partly due to Spanish arrest warrants.
Elsa Artadi, a lawmaker with Puigdemont's Together for Catalonia party, said that he should fight his extradition.