The Vatican has reportedly called on Brazil's government to provide a £26 million bailout to help cover an expected shortfall in funding for the visit of the Pope to Rio de Janeiro later this month.
A deficit in the expected millions of pilgrims - whose contributions were expected to largely fund the cost - led to the Vatican identifying a black hole of up to £44 million, according to Brazilian media.
But Brazil's federal, state and city officials in Rio de Janeiro, who have already committed at least £48 million of public money to the £100 million plus project, are said to have refused to contribute any more.
Pope Francis, an Argentinian, will make his first international trip to the world's largest Catholic country for the World Youth Day celebrations to be held between July 23 and 28.
Local media suggested that recent mass protests across Brazil - where more than a million people demonstrated about the lack of investment in public services when contrasted with mega-events such as the Pope's visit, the World Cup and Olympics - may have played a part in that decision.
The plan was for the pilgrims - who had been expected to number up to two million - to fund up to 70 percent of the costs with payments of between £31 and £175, according to Brazil's O Globo newspaper.
But, so far, only about 320,000 pilgrims have registered, with government officials indicating that they fear perhaps less than half the initial estimate will attend.
According to the newspaper's sources, Vatican officials met with Rio city mayor Eduardo Paes, Rio state governor Sergio Cabral and Gilberto Carvalho, a senior aide to Brazilian president Dilma Rousseff, on Friday and requested that each provide an extra £8.8 million in funding.
The state government is said to have confirmed the existence of the meeting but would not comment on its contents while the Archdiocese of Rio denied the event was in financial difficulties.
Brazil's federal government is already committed to spending £33 million on the event, most of which is being spent on a massive security operation including thousands of military, police and firefighters.
The security operation is said to be unprecedented for a visiting dignitary in Brazil.
Both of Rio's city and state authorities are committed to spending at least £7.6 million on costs such as logistics and free transport for the pilgrims, with fears that both could yet end up spending more.
Some funding for the event, which will culminate in a mass on Copacabana Beach, has also been provided by sponsors, including fast food chain McDonald's.
Last week Brazilian bishops visited the Vatican to report on the protests that have swept Brazil, amid fears that the visit may have to be cancelled if the vast demonstrations continued.