The footballer Lionel Messi could leave Barcelona without a transfer fee if Catalonia secedes from Spain and the club does not compete in any of Europe’s top four leagues, Spanish newspaper El Mundo has reported, citing a clause in his new contract.

Barça’s all-time top scorer signed the contract in November, seven months before his old deal expired. It runs until June 2021 and contains a €700m ($843m) buyout clause.

But according to the Spanish paper it would also allow the five-times world player of the year to leave for free the club where he has spent his entire career if Catalonia’s independence push resulted in Barça exiting Spain’s top flight and not joining either the Premier League, the Bundesliga or Serie A.

A Barça spokesman said: “In the interests of confidentiality the club never comments on contracts signed with players and never will.”

Messi’s management team could not immediately be reached for comment.

The political crisis triggered by Catalonia’s push for independence remains unresolved after separatists won a slim parliamentary majority in a regional election last month.

Messi’s latest contract was signed on 25 November, before that vote but after an autumn referendum on Catalan independence the authorities in Madrid declared illegal.

The referendum had direct ramifications for FC Barcelona who, on the day it was held, chose to play their La Liga game against Las Palmas behind closed doors in response to police violence against people trying to vote.

The president of La Liga, Javier Tebas, has repeatedly said Barcelona would be booted out of the Spanish league along with all other Catalan clubs in the event of secession, as only teams from Spain and Andorra are entitled to compete in the Spanish leagues.

Barça, who have won 24 Liga titles and lead this season’s standings by nine points, said after the referendum they would not speculate on the future.

However, they were “not planning for any other scenario than playing in the Spanish league. The club is competing in this competition and wants to win it”.