A woman was arrested today by detectives investigating allegations of voicemail hacking.
Scotland Yard said the 42-year-old suspect was detained on suspicion of money-laundering offences.
She was held after attending a south west London police station by appointment at around 11am.
She was being questioned by officers from Operation Weeting, Scotland Yard's phone-hacking investigation.
Police launched Operation Weeting, the inquiry devoted specifically to phone hacking, after receiving "significant new information" from News International on January 26 last year.
Operation Elveden was launched months later after officers were given documents suggesting News International journalists made illegal payments to police officers.
Officers also launched three related operations: the Sasha inquiry into allegations of perverting the course of justice; Kilo, an inquiry into police leaks; and Tuleta, the investigation into computer-related offences, as the inquiry escalated.
Metropolitan Police figures showed there were 829 potential victims of phone hacking, of whom 231 were said to be uncontactable.
The scandal has already led to the closure of the News of the World after 168 years, prompted a major public inquiry, and forced the resignation of Met Commissioner Sir Paul Stephenson and his assistant John Yates.