The uncle of missing Sarah Everard has pleaded for anyone who knows what happened to "be human and to let her come home".
Detectives continue to investigate the 33-year-old's disappearance, which happened as she walked home from Clapham to Brixton, south London, on 3 March.
Her family has described her sudden loss of contact as "totally out of character", while police have stressed there is no information yet to suggest "anything untoward" has happened to her.
"If someone is holding her against her will I would plead with them just to be human and to let her come home, to let her talk to us, give us a ring or text to let us know she is OK," her uncle Nick Everard told The Sun.
Watch: Police ‘increasingly concerned’ for woman missing since Wednesday
"These are desperate times for the family.
"We know the police are doing everything they can but it's the not knowing what has happened after four days is agonising.”
Everard left Leathwaite Road at about 9pm and walked on the A205 South Circular, then is thought to have gone through Clapham Common, where searches have taken place.
A new CCTV image, which is believed to have come from a private doorbell-type camera, captured her walking alone on the A205 Poynders road towards Tulse Hill, which is south of Brixton.
The Met has said it was unclear if she had returned to her house.
House-to-house inquiries and searches are ongoing.
More than 750 people have been spoken to as part of the investigation and more than a hundred calls have been received.
Everard was last seen in a green rain jacket, navy blue trousers with a white diamond pattern, and turquoise and orange trainers.
On Monday, Detective Chief Inspector Katherine Goodwin said: "This is definitely a missing person investigation at the moment but I remain open-minded as to all possibilities in the investigation."
A hat found during the search did not belong to Everard, the officer said.
She said previously: "I would like to stress that there is no information at this stage to suggest anything untoward may have happened to Sarah.
"The focus remains on returning her home to her family safe and well and that is our number one priority."
Any footage from drivers on Poynders Road at about 9pm has been requested, which DCI Goodwin said could be "vital".
Her family said: "She is always in regular contact with us and with her friends and it is totally out of character for her to disappear like this.
"We long to see her and want nothing more than for her to be found safe and well."
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