POPE BENEDICT has become seriously ill after visiting his dying brother in Germany.
The former head of the Catholic Church is reportedly "extremely frail" and is suffering from shingles, according to his biographer Peter Seewald.
93-year-old Benedict is suffering from erysipelas of the face - a virus that causes a facial rash and episodes of severe pain, and is apparently so weak that his voice is barely audible, though his "mind and memory are still active".
"According to Seewald, the Pope emeritus is now extremely frail," Germany's Passauer Neue Presse newspaper reported on Monday.
"His thinking and his memory are quick, but his voice is hardly audible at the moment."
The retired pope visited his native Bavaria in June to pay his dying brother - who passed away on June 29 - a final visit.
His brother succumbed to a "serious illness" according to the Church, but they failed to specify the nature of the illness.
This was Benedict's first trip outside of Italy since he resigned the papacy due to health concerns in 2013.
He became the first pope to resign from his post in 600 years.
Since then, he's lived in a small former monastery inside the Vatican.
Benedict has largely avoided the public eye since he stepped down, but has taken to writing several high-profile religious papers ever since, the latest being his biography.
"At the meeting the emeritus Pope, despite his illness, was optimistic and declared that if his strength increased again he would possibly take up his pen again," the paper added.