Pope Emeritus Benedict XVI's health has deteriorated in recent hours, the head of the Holy See's press office, Matteo Bruni, announced Wednesday.

"I can confirm that in the last few hours there has been a deterioration due to advancing age. The situation at the moment remains under control, monitored continually by doctors," the Vatican press office quoted him as saying.

German cardinal and prominent theologian Joseph Ratzinger ascended to the papacy in 2005 after the death of his predecessor John Paul II, taking the name Benedict XVI. In 2013, he became the first pontiff in 600 years to relinquish the papal throne. Benedict, who was 85 years old at the time, attributed his decision to a lack of strength to rule the Roman Catholic Church. Benedict XVI lives on Vatican grounds.