The most likely place for a leak of this kind is the outlet from the drum to the pump - the hose here has a hard life, it is usually some kind of bellows type so that it can move with the motion of the drum, and ends up splitting.
If it's this then the fix is very easy:
1. Unplug (or somehow electrically isolate) and pull out the appliance.
2. Lower the entire drain hose to ground level and drain all the water you can into a bowl.
3. Turn the machine onto one side, preferably with the drain outlet towards the upper side, for convenience.
4. Undo clips that retain the outlet hose, and examine for splits.
5. Order new hose from the manufacturer or spares supplier.
6. Fit new hose with new Jubillee clips of the correct diameter, and don't use any sealant on either end.
7. Put the machine back upright, push back, plus in, switch on, run tests.