A serving Metropolitan Police officer has been arrested in connection with the disappearance of a woman in London, detectives say.
Missing 33-year-old Sarah Everard was last seen in Clapham, south London, on 3 March.
The officer was detained at an address in Kent on Tuesday evening and remains in custody at a London police station, the Met said.
A woman was also arrested at the same address on suspicion of assisting an offender.
Detective chief inspector Katherine Goodwin said: “This is a significant development in our inquiry. This is a fast moving investigation and we are doing everything we can to find Sarah.
“We have seen an overwhelming response from the public and I repeat my request for anyone with information that may be relevant to come forward, no matter how insignificant it may seem.”
Ms Everard disappeared after leaving the home of a friend in Clapham at around 9pm last Wednesday, with footage from a doorbell camera showing the marketing executive walking towards the Tulse Hill area around half an hour later.
Her family have previously described her disappearance as “totally out of character”.
Officers had earlier on Tuesday set up a cordon around the Poynders Court housing complex on the A205 Poynders Road, with forensics officers seen examining the area.
Met assistant commissioner Nick Ephgrave said: “The arrest this evening is a serious and significant development. We will continue to work with all speed on this investigation but the fact that the arrested man is a serving Metropolitan Police officer is both shocking and deeply disturbing.
“I understand there will be significant public concern but it is essential that the investigative team are given the time and space to continue their work.”
The force said it would not be commenting further on the arrests at this stage.
Ms Everard’s family have been made aware of the developments in the case, as have the Met’s Directorate of Professional Standards.