There are many accusations about Catholics and paganism.
Here is one from John Calvin who lived 1509-1564 about the Catholic Church and idols, relics, images, and other superstitions adopted from paganism.
Calvin further quotes an "eminent Roman Catholic writer" 13Chateaubriand Etudes Historiques, vol. ii. p. 101..
The frankincense, says an eminent Roman Catholic writer of our time, the flowers, the golden and silver vessels, the lamps, the crowns, the luminaries, the linen, the silk, the chaunts, the processions, the festivals, recurring at certain fixed days, passed from the vanquished altars to the triumphant one. Paganism tried to borrow from Christianity its dogmas and its morals; Christianity took 015from Paganism its ornaments.13 Christianity would have become triumphant without these transformations. It would have done it later than it did, but its triumph would have been of a different kind from that which it has obtained by the assistance of these auxiliaries. Christianity, says the author quoted above, retrograded; but it was this which made its force. It would be more correct to say, that it advanced its external progress at the expence of its purity; it gained thus the favour of the crowd, but it was by other means that it obtained the approbation of the cultivated minds.14
The church made a compromise with Paganism in order to convert more easily its adherents, See chapter II of same link
Eward Gibbon 1737-1794 writes this about paganism and Catholic Church.
Under the successors of Constantine, in the peace and luxury of the triumphant church, the more prudent bishops condescended to indulge a visible superstition, for the benefit of the multitude; and, after the ruin of Paganism, they were no longer restrained by the apprehension of an odious parallel. The first introduction of a symbolic worship was in the veneration of the cross, and of relics. The saints and martyrs, whose intercession was implored, were seated on the right hand if God; but the gracious and often supernatural favors, which, in the popular belief, were showered round their tomb, conveyed an unquestionable sanction of the devout pilgrims, who visited, and touched, and kissed these lifeless remains, the memorials of their merits and sufferings. The Decline and Fall of the Roman Empire
Albert Barnes 1798-1870 says this about idolatry, about homage paid to the deceased.
(2.) The statement that idolatry was practised, and continued to be practised, after this invasion: "Repented not that they should not worship idols of gold, silver, and brass." On this point, perhaps it would be sufficient to refer to what has been already noticed in regard to the homage paid to the souls of the departed; but it may be farther and more clearly illustrated by a reference to the worship of images in the Romish communion. Any one familiar with church history will recollect the long conflicts which prevailed respecting the worship of images; the establishment of images in the churches; the destruction of images by the "Iconoclasts;" and the debates on the subject by the council at Hiera; and the final decision in the second council of Nice, in which the propriety of image-worship was affirmed and established. Notes on Revelation
Adolf Harnack 1851-1930 mentions Usener 1834-1905 about paganism and the Catholic Church.
Rome, again, from the time of Liberius pursued and explained that religious policy towards paganism, “by which the Catholic Church gained the means not only of winning but of satisfying the masses of the people who were, and, in spite of 60the confession, remained heathen” (Usener, Relig. Unters., I., p. 293): “it rendered heathenism harmless by giving its blessing to it, i.e., to all that belonged to the pagan cultus.” But that magnanimous way of opposing paganism, which has been rightly adduced, and which Usener (op. cit.) has begun to exhibit to us so learnedly and instructively, concealed within it the greatest dangers. History of Dogma V 5
So to answer the OP, yes, there are numerous claims regarding Catholicism and paganism.