Massive Auto Gearbox leak

Have a 2000 2.5 auto, and the gearbox has emptied itself very quickly between the engine and gearbox, got it recovered and got it up in the air, put a couple if litres in it and as soon as it was started, the whole lot pumped onto the floor.



Gonna remove the gearbox today, but has anyone got any ideas as to what this might be before I start.



Many thanks