The former head of Catalonia and other sacked members of the region's government are in Brussels, where they will make a declaration on Monday afternoon, newspaper La Vanguardia said.
Other Barcelona-based paper El Periodico had earlier said Puigdemont was in the Belgian capital, without giving any further detail.
Belgian state broadcaster VRT said on Monday that the former head of Catalonia is on his way to Brussels to see lawyers.
"Carles Puigdemont is almost certainly coming to Brussels and is said to be on the way," VRT said on its website. "Puigdemont will meet lawyers and political representatives here."