Judge Carmen Lamela issued European and international arrest warrants for Carles Puigdemont and four other former Catalan regional ministers on Friday evening, and ordered them to be imprisoned on remand without bail, the National High Court confirmed.
"Carles Puigdemont Casamajó appears to be in Belgium", says the judge.
The warrants are for the crimes of rebellion, sedition, misuse of public funds, abuse of authority and contempt of court.
The judge said Mr. Puigdemont and the others may not appear by video link from Belgium and says they travelled abroad "with the sole aim of evading possible responsibilities they might have in Spain".
The former First Minister of Catalonia, says the judge, "was aware of the radical lack of power of the Autonomous Community of Catalonia to call a referendum" on independence.
Judge Lamela says separatists, led by Mr. Puigdemont as First Minister of "the regional government of Catalonia", "promoted and used the intimidating and violent force of the pro-independence sectors of the population".
They "called for insurrection, against and as a challenge to Spanish constitutional order".
Despite several Constitutional Court rulings ordering him to stop, Mr. Puigdemont "continued promoting the measures needed for the creation of a future independence Catalan state in the form of a republic".
A strategic document called Enfocats "corresponds perfectly with all of the steps executed by the Catalan government" over the past two years.
Catalan separatists wanted, as part of the independence process, to obtain "exclusive control" of the Catalan Police, the Mossos, "a police force made up of more than 17,000 armed officers, with the potential intimidatory effect they represented".
The judge links that plan to seek exclusive control of the Mossos with Article 472.7 of the Spanish Criminal Code 1995, which describes the different actions that constitute the crime of rebellion.
As well as attempting to modify the Constitution, or declaring the independence of part of the national territory, Article 472, in its seventh point, specifies the action of "extracting any kind of armed force from its obedience to the government".
Mr. Puigdemont, says Judge Lamela, "planned, organised and financed the calling and celebration of the referendum on October 1 with public funds".
Regarding the €6.2 million Mr. Puigdemont and the others have been ordered to pay as a civil liability deposit, the judge says public funds were "deliberately" used in a manner that was "radically removed from the public function".