The frosty relationship between two of the world’s most prominent Argentinians appears to have taken a turn for the worse after it emerged that Pope Francis rejected a charitable donation from the government of President Mauricio Macri – at least partly – because the sum included the figure 666.

Earlier this month, the centre-right president made a donation that totaled 16,666,000 pesos (slightly under $1.2m) from the Argentinian government to the Scholas Occurentes educational foundation, which is backed by the pope and is based on a similar organization founded by Francis when he was cardinal of Buenos Aires.

Two weeks ago, the pope presided over an event in Rome at which medals were awarded to Hollywood celebrities George Clooney, Salma Hayek and Richard Gere, who have agreed to be ambassadors for the charity. Shortly afterwards, Macri made the donation.

But according to the Vatican Insider – a publication specializing in papal affairs published by the Italian newspaper La Stampa – Francis wrote to the Argentinian branch of the foundation, asking them to return the money. In a postcript, he wrote: “I don’t like the 666.”

Francis, who has long supported progressive causes in Argentina, and the centre-right president Macri have often found themselves on opposite sides of political debate.

But the pope is reported to have been particularly irritated when the Argentinian media presented the president’s donation as a sign that relations between the two leaders were improving.

The Argentinian chapter of Scholas returned the donation saying that “there are those who are trying to misrepresent this institutional gesture ... with the purpose of generating confusion and division among Argentines”.

Government officials denied that the return of the donation had caused any ill will.

“There is no animosity towards the president,” said foreign minister Susana Malcorra after a meeting with Pope Francis in Rome on Monday. “It was a very rich, very natural conversation, with no calling of accounts or enormous philosophical differences.”

Critics of the Macri administration said that the pope’s rejection of the donation reflected his distaste for the president’s introduction of swingeing austerity measures, such as a 500% hike in home power rates and a 100% increase in transport fares, which have cut deep into the pockets of the working class.

“The 16 million didn’t sound good,” said Juan Grabois, an Argentinian social

activist and Vatican advisor with close links to the pope. “Whoever thinks that by giving money, especially public funds to a foundation directly or indirectly linked to Francis, is making a gesture to the pope, is stupid,” Grabois told Argentinian media.