Opus Angelorum, which means “the work of angels” in Latin, was founded by an Austrian housewife who died in 1978.
She claimed to have identified the angels and demons who were battling for the control of human beings.
The Church said some members of the sect were carrying out “activities that disturb the ecclesiastical community”.
The BBC’s David Willey in Rome says Opus Angelorum first attracted the attention of the Vatican 30 years ago, after the death of its founder, a woman from the Austrian Tyrol called Gabriele Bitterlich.
Bitterlich claimed to have been in contact with an archangel and to have written down the names of hundreds of angels and demons, our correspondent says.
The sect – which operates mainly in German-speaking Europe, Brazil and India – claims that women who have had abortions are possessed by the devil.
The activities of Bitterlich’s followers, including dozens of Catholic priests and nuns, eventually attracted the attention of the Vatican which ordered an investigation, our correspondent adds.
According to a letter sent by the head of the Vatican’s Congregation for the Doctrine of the Faith, in 1992 members of Opus Angelorum agreed to follow the doctrine of the Church in return for official recognition.
However, several members of the sect, including some priests, “have not accepted the norms given by the Congregation for the Doctrine of the Faith and seek to restore what, according to them, would be the ‘authentic Opus Angelorum'”, the letter warned.
Vatican warns bishops of deviant behaviour
A letter to the heads of bishops conferences by Congregation for the Doctrine of the Faith chief Cardinal William Levada claims some members of the movement, including priests, carry out “activities that disturb the ecclesiastical community”.
Levada’s letter, dated October 2 and made public on Thursday, warns that in recent years some members of the movement “have not accepted the norms that have been established … and aspire or work to reestablish what in their view is the ‘real Opus Angelorum,’ that is a movement that would profess or practice all that is forbidden,” by Vatican documents.
“Propaganda in favour of this deviant movement, which is outside all ecclesiastical control, is done in a very discreet way that suggests it is in full communion with the Catholic church,” Levada wrote, calling on bishops to be watchful of disruptive activities and ban those they identify.