A 25-year-old has been arrested on suspicion of harassment by officers investigating Twitter abuse aimed at Caroline Criado Perez, 29, and Walthamstow MP Stella Creasy, Scotland Yard said.
A police statement read:
"This arrest will form part of two ongoing MPS investigations relating to allegations made to police by two separate victims, who made reports of malicious communication to police on 25 and 29 July."
The arrest comes after Labour MP Stella Creasy complained to police after she was threatened with rape on Twitter.
More top news
Pilots with a history of depression should not be banned from flying, a leading British psychiatrist has said.
Parents have been told by teachers they'll be reported to police and social services if children to play Call of Duty or Grand Theft Auto
TV presenter Alice Beer has said the pair received similar kidnap and rape threats just weeks before the Crimewatch star was murdered.