At the time, Spain's National Police confirmed it with a tweet, but now the Spanish government has changed its story and publicly denies that Spanish police played a part in arresting Catalan president Carles Puigdemont in Germany. The version, as widely reported three months ago, was that an international cooperation unit of the Spanish police, in coordination with the CNI - the Spanish intelligence service - had worked together with Germany's Federal Office of Criminal Investigation to arrest Carles Puigdemont on 25th March. But now the Spanish authorities wash their hands of this and simply assert that "the German authorities are sovereign to act in their territory to comply with an European arrest warrant, taking the measures that they believe pertinent."
So under the new version, Spain's National Police had nothing to do with the arrest of Puigdemont. This new positioning by the Spanish government was confirmed by an answer to questions asked in the Spanish senate by Jon Iñarritu, of the Basque party EH Bildu, on 19th April, in which he questioned the CNI's espionage, affirming that if it really did take place in the way that police sources and many different media described, it was against German law. In fact, as the law states, "the activities of foreign services against the German Federal Republic are punishable under article 99 of the German Criminal Code", if they are not authorized.
According to the Spanish police's initial version, the CNI monitored Carles Puigdemont's journey by car from Finland until he was stopped in Germany (link in Catalan). They even boasted on Twitter that "thanks to a coordinated operation by [Spanish] information area police and Spanish intelligence, Puigdemont has been detained in Germany".
The Basque senator thus raised several questions in Spain's upper house: whether the German authorities had knowledge of this espionage, what the nature of the collaboration was between the police authorities of the two countries and the means used to carry it out, how the action was authorized in German territory and what was the reason for waiting until Puigdemont entered German territory to request his arrest. And these questions remained unanswered for two further months - until this week - and the responses given now have denied any Spanish responsibility in the matter: "It should be noted that no Spanish technical or human means took part in the detention of Carles Puigdemont i Casamajó", says the government's official response to the Senator.
Translation: Well! Remember when all the Spanish media were celebrating that the detention of president Puigdemont had been possible thanks to a large deployment of Spanish agents? Now the government says it has nothing to do with his arrest... #FreedomPoliticalPrisoners — Jon Inarritu
Given all of this, exiled president Puigdemont has commented that "they followed me illegally and they must respond to justice, real justice", but he puts a positive reading on it, being convinced that "states under a rule of law investigate these crimes and bring those responsible to justice. They do not hide them under a carpet".
Later, Puigdemont reiterated that the Spanish government "must give an explanation and accept responsibilities" because, he noted, there are people in prison and in exile "due to falsehoods such as these... and others that people will eventually hear about".
Some European politicians, such as the Finnish interior minister Kai Mykkänen, spoke out at the time to state very clearly that the espionage undertaken by Spanish intelligence had been completetly irregular and without authorization.