Wicket keeper

27.5 RESTRICTIONS ON ACTION OF WICKET-KEEPER

The wicket-keeper must not interfere with the striker when he is

playing at a delivery
or
attempting to guard his wicket

Either umpire can decide that the wicket-keeper has transgressed

      if considered accidental

            call and signal Dead ball

      if considered deliberate

            Law 41.4 (Deliberate attempt to distract striker) will apply