The BBFC cut the scene in which Honor Blackman is killed for an A rating back in 1968. Unfortunately their Register entry just refers to ‘reduce’ rather than being specific.
However it used to play on UK TV with the sequence heavily cut and edited to imply that the Indian had suffocated her with sand in her mouth (removing the subsequent tossing about of her from Apache to Apache and the necklace suffocation- did Dario Argento see this as there is a similar death in Opera).
I always assumed that the cut version was the original UK cinema print although I could be mistaken.