An Italian journalist who beat the world's media on Pope Benedict XVI's decision to resign got the scoop on the utterly unexpected news thanks to her knowledge of Latin.

"Our Vatican expert Giovanna Chirri was listening to the pope's speech," the ANSA news agency's head of information Luigi Contu told AFP.

"At one point, the pope stopped talking about the consistory. Chirri understood he was saying he was tired, that the pressure was too much, and that he was going to stop," he said.

Chirri rushed to call Vatican spokesman Federico Lombardi to confirm the news but got no reply.

In a heated debate with her editor, the journalist insisted her Latin knowledge was sound and they could alert the news.

At that point Lombardi rang back and at 11:46 am (1046 GMT) ANSA's alert was picked up by news agencies around the world.

"This is a strong argument for culture in training future journalists," Contu said with a chuckle.

Congratulated by her colleagues, Chirri played down her success, tweeting: "Benedict XVI's Latin is very easy to understand."