Professor Clara Ponsati, the ex-Catalan education minister, is being sought by the authorities in Madrid on charges of “violent rebellion and misappropriation of public funds” over her role in Catalonia’s controversial independence referendum last year.
She refutes the charges and has embarked on a legal fight to resist the attempts to have her returned to Spain.
Scottish-based Prof Ponsati attended a police station in Edinburgh voluntarily on Wednesday morning after she was made the subject of a European arrest warrant last week.
She was placed under arrest and formally had the European Arrest Warrant read to her.
The academic appeared from custody at an initial hearing at Edinburgh Sheriff Court.
The hearing before Sheriff Nigel Ross lasted less than 10 minutes on Wednesday afternoon with a number of her supporters present in the packed court room.
The court heard Prof Ponsati does not consent to extradition and the application for bail was not opposed by the Crown.
She was granted bail and asked to surrender her passport.
Her lawyer says she views the charges - which could attract a jail term of up to 30 years - as “political persecution” and believes that her human rights cannot be guaranteed in Spain.
Solicitor, Aamer Anwar, said earlier: “Clara remains defiant, resolute and is determined to fight back.
“She wants to thank the many hundreds of thousands of ordinary people especially in Scotland who have shown her such love and support.
“She is truly humbled by the unconditional support from students, colleagues and the principal at St Andrews University.
“Clara wishes to thank Nicola Sturgeon, the Scottish Government and politicians for their solidarity. Scotland has been a true friend to Catalonia in her darkest hours.”
Prof Ponsati returned to Scotland earlier in March having been in Belgium since fleeing Spain with Catalonia’s ex-leader Carles Puigdemont and three other former cabinet members, following an unsuccessful bid to declare independence from Spain in October.
She had resumed working at the University of St Andrews in Fife.
But a Spanish judge issued arrest warrants on Friday for Prof Ponsati and the other fugitive politicians including Mr Puigdemont, who was detained by police in Germany.
A crowdfunding drive to raise money for Prof Ponsati’s extradition defence reached £100,000 just over two hours after it was launched on Wednesday morning.
On Monday, a group of protesters congregated outside the Spanish consulate in Edinburgh to demonstrate against the arrest warrant and the actions of the Spanish Government.
At the police station on Wednesday Xavier Oliver was one of a number of people who turned up to show support for Prof Ponsati.
The 35-year-old software engineer from Catalonia said: “The Spanish Government is using this excuse to put people in jail and let them rot.
“They should tackle the problem politically. In their minds putting people in jail on ridiculous charges is enough to change the minds of two million people.