This one is not it. But, it suffices to show that such groups exist. Also, note, "OFFSHOOT" not the Church itself
"In September, for instance, Dominic Sanchez Falar founded the “Mary is God Catholic Movement”, which claims that the third secret of Fátima revealed Mary’s divinity. This secret was covered up, he says, by Pope John Paul II and Cardinal Joseph Ratzinger, now Pope Benedict XVI. Rantings of this kind would be risible were they not gaining so much currency, particularly in the US."
http://www.catholic-pages.com/forum/topic.asp?ARCHIVE=true&topic_id=6901
http://www.maryisgod.org/
Pope Benedict, for one, takes [the false seers] seriously. Three years ago, while Prefect of the Congregation for the Doctrine of the Faith (CDF), he said that private revelations posed a threat to the unity of the Church and warranted an “exemplary pastoral response” from the Holy See.[...]
Benedict is now already moving against private revelations in a way his predecessor did not. Two cases signal his intent. Barely a month after his election, the CDF issued two documents. One was a decree removing Father Gino Burresi from active ministry, and the other was a letter to the Filipino bishops effectively declaring as false the claims of Ida Peerdeman, a Dutch seer, that the Virgin Mary had revealed new truths about her status
[...]
Cardinal Joseph Ratzinger thought that Burresi was a fraud, was guilty of “pseudo-mysticism” and “asserted apparitions, visions and messages attributed to divine origins”.
The CDF stripped Burresi of the right to hear confessions, preach, give interviews, publish or broadcast.