Heather Mills has attended a police station in Hove to speak to officers there. A spokeswoman said of Paul McCartney's ex-wife to be: "It was a pre-planned meeting did not relate to anything specific and she was not arrested". Why one might have thought she had be arrested isn't clear to me; as far as I know there's no actual law against being irritating.
A spokesman for the former model, Phil Hall, said he had not spoken to her, but confirmed that she had been in "ongoing communication" with police about those previously reported death threats.