He had arranged the marriage of his daughter, however, she wanted to run away with one of the servants and asked for the help of Carlo Grimaldi. Carlo told them to come to a boat that same night.
In secret, Carlo informed Ignazio about his daughter's intentions. She and the servant appeared at the boat that night, only to find Ignazio and Carlo there. Ignazio had the servant killed and thrown into the river. Later, Ignazio had awarded Carlo with a seat on the Council of Ten, for his dedication to the Contarini family.