Legal experts say extradition would take 15 days - unless the process is appealed
Belgium's State Prosecutor's Office has said it is studying European Warrants issued for ousted Catalan president Carles Puigdemont and four other separatist leaders
Mr Puigdemont and the four ex-members of his cabinet travelled to Brussels on Monday after being accused of rebellion, sedition and misuse of public funds.
National court judge Carmen Lamela has filed a request with the Belgian prosecutor to detain the five - and also issued separate international search and arrest warrants to alert Europol in case they flee the country.
She rejected a request from Mr Puigdemont to testify via video conference from Brussels.
"We're going to study (the EU arrest warrants) and give it to a judge," a spokesperson for Belgium's state prosecutor said.
If they are arrested by Belgian police, Mr Puigdemont and his colleagues would have to be brought in front a judge within 24 hours.
Belgian legal experts say extradition would take 15 days.
However, if the politicians appeal the process it could take a further 45 days - giving them enough time to participate in the region's snap election on 21 December.
Earlier, Mr Puigdemont vowed to stand in the poll, insisting that it is “possible to run a campaign from anywhere."
Insisting he "will not run from justice," Mr Puigdemont told Belgian media: "I will go to the justice authorities, but the real justice authorities.”
"I have told my lawyer to tell Belgian justice authorities that I am completely ready to cooperate."
The deposed Catalan leader added that it was "very clear that the Spanish justice authorities had become politicised."
On Thursday, Judge Lamela ordered eight regional ministers, including deposed vice president Oriol Junqueras, to be remanded in custody while possible charges are considered.
She also detained another separatist politician, pending a €50,000 (£38,290) bail payment.
Minister Santi Vila - who resigned from Mr Puigdemont’s government a day before the independence declaration - was released from custody on Friday after posting bail.
In a tweet Mr Puigdemot warned that his colleagues had face "ill-treatment" when they were sent to prison.
Mr Puigdemont had also been ordered to appear before a court in Madrid, but ignored the request.
Reacting to the jailing of his colleagues, Mr Puigdemont said on Twitter that "the legitimate government of Catalonia has been jailed for its ideas."
Posting a photo of protesters, he added: "The serene clamour of the Catalans is of freedom."