Catalonias deposed separatist leader Carles Puigdemont will not return to Spain to face a top criminal court on Thursday, as there is a "good chance that he would be detained", his lawyer has said.

Speaking to Dutch public newscaster NOS late Tuesday, Belgian lawyer Paul Bekaert said "as far as he told me that's not going to happen" when asked if his client would go back to Spain having been summoned to appear in a Madrid court.

"That's because we are awaiting further reactions from the Spanish authorities to see what's going to happen," Bekaert said, speaking by phone to the Nieuwsuur news programme.

Puigdemont together with 13 other former members of his administration, dismissed by the Spanish central government last week, has been summoned to appear by the National Court in Madrid, Spain's top criminal tribunal.

On Monday, Spain's chief prosecutor said he was seeking charges of rebellion -- punishable by up to 30 years behind bars -- sedition and misuse of public funds.

The National Court told Puigdemont and his 13 deputies to appear for questioning in Madrid on Thursday and Friday and gave them three days to pay a combined deposit against potential penalties of 6.2 million euros ($7.2 million).

Prosecutors could order their arrest if they failed to appear.

But Puigdemont, 54, is in Brussels, where he surfaced after reportedly driving to Marseille in France and flying to the Belgian capital.

"I don't forsee him going back to Spain within the coming weeks," Bekaert told VTM.

He said he believed "there is a good chance Puigdemont will be detained" should he return.

Asked by NOS whether Puigdemont would face a fair trial in Spain, Bekaert said: "It would be premature (to say), but that would certainly be an argument we would use at an eventual extradition request".

He added that an extradition request from Madrid "is not essential".

"I have handled a large number of cases involving Spanish Basques and in those cases an interrogation simply took place here (in Belgium) with local police," he said.

Bekaert told VTM however that "when Spain asks for his (Puigdemont's) extradition a Belgian judge would have to make a decision about it."

"Therefore it's not the (Belgian) government that decides about the extradition, it's the courts," he said, adding his client would not seek political asylum in Belgium.

"You can request asylum, but seldom or never is it given," he said, adding his four previous attempts to win asylum for different clients had all ended in failure.

At a chaotic news conference Tuesday in Brussels, Puigdemont said he was in the Belgian capital "for safety purposes and freedom" and to "explain the Catalan problem in the institutional heart of Europe".

He denied he intended to claim asylum but said he and several other former ministers would only return if they are guaranteed impartial legal proceedings.