The cases are expected to be brought up on Friday at the Vatican when Bishop Robert Zollitsch, the head of the German Bishops Conference, holds a regular meeting with the pope.
The allegations are particularly sensitive because Germany is the pope's homeland and because the scandals involve the prestigious Domspatzen boys choir that was led by his brother from 1964 till 1994.
Juesten said it was not known if the pope, who served as Archbishop of Munich and Freising from 1977 to 1981, was aware of any of the child abuse cases that took place then at Catholic schools and other institutions.
"We do not know if the pope knew about the abuse cases at the time," Juesten said. "However, we assume that this is not the case".
Juesten said that Archbishop Reinhard Marx of Munich would be "certainly investigating these questions".
Ratzinger, the pope's older brother, apologised to victims on Tuesday for doing nothing decades ago to stop the beating of students.
Juesten called Ratzinger's apology to the victims an act of courage.
"It is certainly not easy for such a man to publicly apologise," Juesten said.
Ratzinger says students told him of allegations of physical abuse at an elementary school in Germany decades ago and apologised for doing nothing about it.
He had at first said he was unaware of any abuse, and Juesten said that others should follow the 86-year-old Ratzinger's lead in coming clean.
"The other perpetrators should follow the example set by Mr Ratzinger and apologise to the victims for the abuse they have committed," Juesten said.
However, the pope's brother has said he was unaware of allegations of sexual abuse at his own Regensburger Domspatzen boys choir, incidents alleged to have occurred before Ratzinger led the choir.
"These things were never discussed," Ratzinger told the Passauer Neue Presse newspaper.
"The problem of sexual abuse that has now come to light was never spoken of."
Ratzinger did admit to slapping students in the face as punishment for many years, but said he was happy when corporal punishment was made illegal in 1980.
|Ratzinger, right, admitted slapping students in the face as punishment for many years [EPA]
Corporal punishment was standard in German schools until the reform movement of the 1960s implemented a non-violent approach.
The allegations from one elementary school at Etterzhausen, however, go far beyond the norm.
In one case, a student reported that a teacher broke a chair over his back.
The schools at Etterzhausen and Peilenhofen, where severe beatings have been reported, were two feeder schools for Ratzinger's choir.
Ratzinger said on Tuesday that boys had told him about being mistreated at Etterzhausen but he did not understand how bad it was and did nothing.
The German government has also announced plans for "round table" meetings involving school, church and other representatives to work on ways of detecting, preventing and dealing with future abuse.
The first meeting is set for April 23.