Complex sentence: In both cases it was hinted or outright claimed that Rottiers respectively his son had dug up at least part of the antiquities themselves, and in both cases it would turn out that perhaps all of the collection was bought.
Split into simpler sentences: In both cases it was hinted or outright claimed that Rottiers respectively his son had dug up at least part of the antiquities themselves. However in both cases it would turn out that perhaps all of the collection was bought.