Former pope Benedict XVI, 93, was seriously ill after a visit to Germany, it has been reported.
German newspaper Passauer Neue Presse reported on Monday that Benedict had become frail and his voice was barely audible, according to his biographer Peter Seewald.
But the Vatican has responded to the report saying Benedict’s condition “was not particularly worrying” and reassured the public he was overcoming a painful but not grave ailment.
Mr Seewald told the newspaper that the ex-pontiff was suffering from shingles, a viral infection that causes painful rashes.
“The health conditions of the Pope Emeritus are not particularly worrying, apart from being those of an old man of 93 who is overcoming the most acute phase of a painful but not grave illness,” said the Vatican in a statement.
Benedict resides in a former convent in the Vatican gardens. He left Italy for the first time since his resignation in 2013 for a farewell visit to his older brother Georg in Bavaria, where they were born.
Georg Ratzinger died on 1 July aged 96. Both brothers were ordained priests on the same day in 1951.
While on his four-day visit to the Bavarian city of Regensburg, Benedict was visited by Mr Seewald, who said the former pope told him he might pick up writing again if he regains his strength.
Benedict was the first pontiff in 600 years to resign from the post, and was succeeded by Pope Francis.
Additional reporting by agencies