From TARDIS Index File, the free Doctor Who reference.

The Hecate Cult was a coven of witches based in Moreton Harwood which worshipped Hecate. The cult's leaders were Commander Bill Pollock, and the local postmistress, Lily Gregson. Known members included farmer George Tracey, his son Peter and policeman Sergeant Vince Wilson. They attempted to sacrifice Brendan but were thwarted by Sarah Jane Smith and K-9. They were arrested and put in jail. About half of Moreton Harwood's residents were members of the cult. (KAC: A Girl's Best Friend)