Organisers of the Catholic youth festival in Sydney say they borrowed a gray cat named Bella to help the feline-loving pontiff pass the time at his retreat in Australia's bush country, according to front-page stories in Australian newspapers on Tuesday.
But Vatican spokesperson Federico Lombardi, pressed by reporters, said he has no knowledge of any cat.
And so is born another of those Vatican mysteries that surround the personal lives of popes. Vatican officials are reluctant to reveal even small details out of both respect for a pontiff's privacy and fear of damaging the position's mystique.
Looked after strays
Reporters are not allowed inside the compound and the only visitors so far have been aides, a few high-ranking Australian church officials and members of a local symphony orchestra that played on two successive days for the pope.
Sydney newspapers also reported that the pope was sent a cake in the form of a grand piano - a reference to his favourite pastime.
The pope is known to like cats and before he became the pontiff he looked after strays in his old neighbourhood near the Vatican, according to the accounts of fellow residents.
When he assumed the papacy three years ago, Vatican officials were quick to shoot down reports that the new pontiff was actually keeping a pet, allowing only that he had a porcelain cat in his apartment.
His love of cats inspired a book on his life that was published last year. In Joseph and Chico: A Cat Recounts the Life of Pope Benedict XVI, the orange tabby tells readers the pope is "my dearest friend, a wonderful man with whom I've spent many happy moments."
Pilgrimage to Australia
The feline narrator is inspired by a real orange tabby cat in Pentling - the German town where the pope, then Joseph Ratzinger, lived for a period before moving to Rome - that belonged to the family next door.
Although there is an unwritten rule that pets are barred from the Vatican palace where popes reside, there is considerable lore regarding supreme pontiffs and their pets.
Pope Leo XII (1760-1829) reportedly kept a small dog. And by many accounts Pope Pius XII had a canary that was spirited away during the night by his housekeeper upon his death in 1958.
Pope Benedict is making a 10-day pilgrimage to Australia to preside over the church's World Youth Day, which has drawn about 200 000 pilgrims. He will make his first official appearance on Thursday.