Refutation from Catholic Answers:
This is a myth that always comes up but is simple to answer. At the Council of Rome in 382, the Church decided upon a canon of 46 Old Testament books and 27 in the New Testament. This decision was ratified by the councils at Hippo (393), Carthage (397, 419), II Nicea (787), Florence (1442), and Trent (1546).
Further, if Catholics added the deuterocanonical books in 1546, then Martin Luther beat us to the punch: He included them in his first German translation, published the Council of Trent. They can also be found in the first King James Version (1611) and in the first Bible ever printed, the Gutenberg Bible (a century before Trent). In fact, these books were included in almost every Bible until the Edinburgh Committee of the British Foreign Bible Society excised them in 1825. Until then, they had been included at least in an appendix of Protestant Bibles. It is historically demonstrable that Catholics did not add the books, Protestants took them out.