His brother, George Ratzinger, on Thursday said his condition was critical and added that he feared the paralysis could spread to Benedict’s heart.
Benedict, a German, who in 2013 became the first Pope in six centuries to resign, said earlier in the month that he was in the last phase of life and on a “pilgrimage toward home”. He is 90 years old.
Breaking News: Pope Benedict in a very critical condition
Ratzinger, 94, told the Neue Post that his brother was mentally fit but tired easily.
“The greatest fear is that the paralysis could at some point spread to his heart.
“Then, it could be over quickly,” he said, adding that he was praying daily for a “good” death for himself and his brother.
He disclosed that they spoke every day on the telephone, saying “that is a great gift; in this way, no one is alone”.
“I very much hope that I can travel one more time to Rome to celebrate the 91st birthday of my brother on April 16.
“But that is a long time away; who knows what will happen by then,” Ratzinger said.
Since resigning, Benedict has been living in a former convent in the Vatican gardens and makes only rare public appearances.