The Vatican has put Spanish architect Antoni Gaudí on the path to sainthood in recognition of his "heroic virtues".

Gaudí - who has been dubbed by some as "God's architect" - is the designer of one of Spain's most famous religious sites and tourist attractions, the unfinished Sagrada Familia basilica in Barcelona.

On Monday, the Vatican issued a statement which said Pope Francis had authorised a decree declaring the Catalonia-born architect "venerable".

That is an early step on the road to a candidate for sainthood being formally canonised by the Catholic Church.

It is the latest development in a decades-long campaign to have Gaudí, who was a devout Catholic, recognised as a saint.

The Archbishop of Barcelona, Cardinal Juan Jose Omella, called the news a "joy".

"It is a recognition not only of his architectural work but something more important," he said, according to AFP news agency.

The cardinal continued: "He is saying you... amid life's difficulties, amid work, amid pain, amid suffering, are destined to be saints."

The usual formal process for someone to be declared a saint would next involve beatification, one step short of full sainthood.

That is a category reserved for martyrs, those deemed to have lived a life of heroic values and candidates who the Church declares to have a saintly reputation.

In the case of Gaudí, who died in 1926 after being hit by a tram while walking to church, the Vatican would likely require proof of a miracle that could be attributed to him post-death in order to proceed with beatification.

Gaudí was born in 1852 and many of his best known works continue to attract visitors to Barcelona, where much of his legacy is situated.

The Sagrada Familia basilica has been under construction since 1883 and remains unfinished.

It has been placed on UNESCO's World Heritage list, along with some of Gaudi's other works, and was consecrated by Pope Benedict XVI in 2010.