Prepare the barbecue for direct cooking over high heat (230°C to 260°C).
To butterfly the prawns, remove the head. Lay the prawn onto a chopping board, place your hand, flat on top of the prawn to hold it in place. Using a sharp serrated knife, such as a bread knife, horizontally cut along the back of the prawn shell. Cut through the flesh from top to tail, but leave the opposite side of the outer shell intact. Open the prawn like a book. Using the tip of a knife, remove the vein. Repeat for each prawn
Drizzle the olive oil over the flesh side of the prawns. Sprinkle with the crushed garlic, lemon zest, smoked paprika, salt and pepper.
Barbecue the prawns over direct high heat for 2 minutes on each side.
Serve with the lemon wedges