@caz845 this is hopefully one of the models with the low profile agitator.
I suggest that you remove the agitator and take a look at the underside. See if the splines are worn on the agitator and/or the shaft. Also make sure that the shaft assembly is not loose and still sits properly in the drum. Post some images of all this with your question. Use this guide for that. It will allow us to see what you see.
My concern here is that the water should not leak out unless there is a misalignment of the shaft/bearing assembly.
10.15 Removal of Low Profile Agitator
Note: Removal of low profile agitator is not intended to be done by the user, as regular maintenance in this area should not be required.
(a) Lift the lid and remove the low profile agitator cap by using an appropriate flat bladed screwdriver in one side of the slots. Lever the cap upwards until it disengages. The cap can then be removed by hand.
(b) Remove the bolt by turning anti-clockwise using a 7/16th (13mm) open-ended spanner or an adjustable spanner.
(c) Remove the low profile agitator.
Note: If the low profile agitator does not lift off easily, hold the top balance ring of the inner basket, and then jerk the bowl upwards. This action will push the agitator upwards.
(a) Refit the agitator, ensuring that it is pushed as far down as it can go.
(b) Insert the bolt into the shaft. Hand tighten until the first click has been felt, then using the open-ended or adjustable spanner, tighten a further 4 more clicks. Over tightening will cause excessive damage to the castellations on the agitator, and may cause the head of the bolt to shear off.
Failure to tighten the bolt correctly will cause the agitator to lift off the spline on the shaft during wash.
(c) Fit the cap to the top of the bolt. Using your hand, hit firmly on top of the cap until the clips on the cap engage to the bolt.