Remove crusts from bread and roll bread that with a rolling pin.

Combine tuna, curry powder, sauce and vinegar in a bowl. Mix together with a fork until tuna is evenly broken up.

Place a spoonful of tuna mixture on each slice of bread. Roll up and secure with toothpicks. Place rolls on a greased baking tray and brush rolls with melted butter.

Bake at 190 Degrees Celsius for 15 minutes or until bread is brown and crispy. Serve hot or cold with tomato sauce.