The Vatican has denied reports that Pope Francis has a brain tumour.

An Italian national newspaper has been lambasted three times by the Vatican for spreading a story that the pontiff had brain cancer. Quotidiano Nazionale ran a story on its front page today claiming that a Japanese doctor had flown to the Vatican to examine the pope "some months ago."

Under the headline "The Pope is Sick", it said the Argentine pontiff was diagnosed with "a small dark spot on the brain", but that it was curable without surgery.

"I am able to confirm that the pope is in good health," chief spokesman Father Federico Lombardi said in a statement he read out during a news conference on another topic.

"The Pope is carrying out his activity with his usual high level of intensity.

"Spreading unfounded news is gravely irresponsible and is not worthy of attention," said Lombardi, repeating an earlier condemnation of the report.

"If you had to run after him during his overseas trips, you'd know [that he is in good health]", said clearly irritated Lombardi.

"He does have some problems with his legs but the head seems to me to be working absolutely perfectly."

However the director of Quotidiano has stood by his paper's report.

"This denial is understandable and to be expected," he said. "We waited a long time before publishing the report in order to carry out every possible check. We don't have the slightest doubt that it is founded."

Whether or not the rumours are true, Pope Francis is maintaining his intense work schedule. His recent tour of the United States was particularly gruelling and is currently preparing for a five-day visit to Kenya, Uganda and the Central African Republic.

Today he spoke, as usual, at his weekly audience in St Peter's Square where, incidentally, he made comments touching on the theme of failing health.