Some senior nuns are abusing their power, including by denying sisters healthcare and warm clothes, a report in a Catholic journal said on Friday.
The Jesuit review Civilta Cattolica said that the problem of abuse of power by senior nuns "has not so far had sufficient attention".
The abuse "mostly does not take the form of sexual violence and does not concern minors," the journal noted.
Some mother superiors cling to power for decades or bring members of their own family to live in the convent to be "hosted and cared for for free".
These relatives can end up being buried with members of the convent.
One mother superior "took her mother into the sisters' community until her death, allowing her to share the community space for about 20 years."
"Every summer she left the community to take her mother on holiday," the article said.
Being a superior, in some cases, "seems to guarantee other exclusive privileges, such as taking advantage of the best medical care, while a simple nun cannot even go to an optician or dentist, because 'one has to save money'", it said.
Some nuns have requests for warm clothes turned down because the convent says it doesn't have money.
"The superior's closet is full of clothes bought with community money without consulting anyone, while others barely have a change of clothes," the report said.
"Unfortunately, for some sisters this is the daily reality: a reality that for the most part they can't make known, because they don't know where to turn, or for fear of retaliation."
Complicity between the mother superior and the convent bursar "ends up allowing complete control of assets".
The message that is given is that "governing is synonymous with privilege, to the detriment of the weakest", while the convent "is more like a prison than a community".
In January, Cardinal Joao Braz de Aviz revealed that former nuns "abandoned" by the Catholic Church, including some who became prostitutes to survive, had been sheltered at a Vatican residence set up by Pope Francis.
In some cases, mother superiors had withheld documents from nuns who wanted to leave the convent, and in others nuns were just told to leavet, the Brazilian cardinal said.
Since becoming pope in 2013, Francis has often focused on helpless members of society, whether migrants fleeing persecution and famine, or the homeless, prisoners and prostitutes.