A curved-hilt lightsaber was constructed by and served Jedi Master-turned-Sith Lord Dooku up until his death during the Battle of Coruscant. The weapon itself was destroyed along with his body when General Grievous' cruiser, the Invisible Hand, broke in half, the rear portion containing the lightsaber burning up in Coruscant'satmosphere.

Source: Starwars.wikia.com