Fugitive Catalan ex-leader Carles Puigdemont has been arrested in Germany, police in the state of Schleswig-Holstein said in a statement.
Puigdemont was stopped near the Danish border with Germany, a spokesperson of his party said on Sunday.
The ex-leader is being sought by Spanish authorities on charges of rebellion, after he led his separatist movement in a bid for an independent Catalonia.
Puigdemont had recently left Finland before authorities there could act on a European warrant against him.
German police said they arrested Puigdemont in the northern state of Schleswig-Holstein on the arrest warrant, which was issued by Spain.
In a statement, police said the Catalan ex-leader was arrested near a section of the A7 highway, which cuts through the state from the city of Flensburg near the Danish border.
Police did not say exactly where Puigdemont was being held.
"Schleswig-Holstein police are at this point in time unable to provide more details," it said, other than that Puigdemont was taken into custody at 11:19am (09:19 GMT).
Prior to his detention in Germany, the former Catalan leader was visiting Finland for talks with legislators.
On Saturday, his lawyer confirmed that he left the country to go back to Brussels, where he lives in self-imposed exile.
Catalonia protests
Tensions are running high in Catalonia, as separatists abandoned plans to name a new president following the arrest of the latest candidate, Jordi Turull.
On Friday, the Spanish Supreme Court issued international arrest warrants for six other separatists, all of whom have fled abroad.
Spanish police also arrested five separatist leaders for their role in last year's independence referendum.
Thousands of protesters responded by taking to the streets of Catalonia on Friday, which resulted in clashes with riot police, leaving 24 protesters lightly injured.
The protests had been called on Thursday, by the Committees for the Defence of the Republic, before the court decisions.
The Supreme Court announced it would prosecute 13 key Catalan separatists for "rebellion", a crime that carries a maximum penalty of 30 years in jail.
Meanwhile, the Barcelona-based Catalan parliament suspended its debates on Saturday after a regional presidential candidate, Jordi Turull, who was seeking a second-round vote in parliament, was taken into custody.
If a new president is not elected by May 22, new elections will have to take place.
Catalonia will remain under direct rule by Madrid as long as it fails to form a new government. The direct rule was imposed after the independence declaration in October 2017.
