The 33-year-old has not been seen since Wednesday, 3 March, when she left a friend's house in Clapham Junction at around 9.00pm and began walking home to Brixton.
The arrest this evening is a serious and significant development.
A serving police officer has been arrested on suspicion of murder.
The case garnered significant public interest and media coverage in the United Kingdom with extensive searches conducted across the area where Ms Everard was last seen.
Detectives were searching locations in London and a house and woodland in Kent following the arrest of the officer and the woman.
Police release footage taken from a private doorbell-type camera showing Ms Everard was walking alone along the A205 Poynders Road towards Tulse Hill, just south of Brixton.
"Sarah's family has been kept updated of these developments".
Human remains have been discovered today in the search for missing woman Sarah Everard in Britain.
Police officers close off access to Fridd Lane near Ashford Kent
The IOPC is now assessing whether any further measures should be taken in relation to the actions of police after Ms Everard was reported missing.
Ms Everard was wearing a green rain jacket, navy blue pants with a white diamond pattern, and turquoise and orange trainers - and is thought to have been wearing green earphones and a white beanie hat too. She was last seen wearing a green rain jacket, navy blue pants with a white diamond pattern and turquoise and orange trainers, and was thought to have been wearing green earphones and a white beanie hat.
She is thought to have walked through Clapham Common on her way home, a trip that should have taken less than an hour.
Dame Cressida continued: "Sarah's disappearance in these terrible and wicked circumstances is every family's worst nightmare".
Metropolitan Police said it had visited 750 homes in the area and taken more than 120 calls from the public.
"We have seen an overwhelming response from the public not only in terms of information that has come into us; but also how social media is being used to share the appeals far and wide. This is a fast-moving investigation and we are doing everything we can to find Sarah".
She was also thought to be wearing green headphones and a white beanie hat.
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