POLICE are on the hunt for ex-Catalan president Carles Puigdemont following his return to Spain after seven years in exile.

On Wednesday, Puigdemont announced that he intended to be present at the investiture ceremony of the new president at the Parliament of Catalonia in Barcelona on Thursday.

This is despite the fact that an outstanding warrant for his arrest remains active.

Last year, Spain’s parliament passed an amnesty law for those charged with crimes relating to the 2017 Catalan independence referendum.

However, the country’s Supreme Court has refused to apply the law to Puigdemont.

Still, on Thursday morning Puigdemont defiantly appeared in Barcelona and was greeted by large crowds after travelling from Belgium.

Several thousand pro-independence supporters had gathered in a central park in Barcelona to welcome Puigdemont, who punched the air to rapturous applause and stated: "Holding a referendum is not and will never be a crime."

But Puigdemont disappeared soon after the appearance, with Spanish media reporting that police have launched an operation to locate and arrest the politician.

READ MORE: Police search sewers as Carles Puigdemont vows return to Spain

It is unclear how authorities would proceed if Puigdemont is arrested given the ongoing dispute about the application of the amnesty law between the Spanish parliament and the Supreme Court.

A security ring has been placed around the Parliament of Catalonia, with police reportedly searching sewers and basements ahead of the swearing in of Salvador Illa of the Socialists’ Party of Catalonia, who eventually emerged victorious after May’s elections which led to months of deadlock between Illa’s party and Esquerra Republicana.