Nine months after Pope Benedict XVI caused global outrage by rehabilitating a Holocaust-denying prelate from a Swiss-based brotherhood, dialogue has re-opened.
The "doctrinal consultations" with the Swiss-based seminary took place behind closed doors, the Vatican confirmed on Monday, with neither side wanting to comment.
In January the pope welcomed back into the Roman Catholic Church four bishops from the Society of St Pius X who were excommunicated in 1988 after being ordained without Vatican permission. The three had been appointed by breakaway French Archbishop Marcel Lefebvre.
But one of the four, the British-born Richard Williamson, has made statements denying the full extent of the Nazi holocaust.
While the Roman Catholic Swiss Bishops Conference and the International Seminary of Saint Pius X, which was founded in canton Valais, welcomed the move, Swiss Jewish groups were highly critical. Many newspapers also expressed their surprise.
swissinfo.ch and agencies