Police searching for the missing Sarah Everard remain "open minded as to all possibilities" over her disappearance.
The 33-year-old has not been seen or heard from since departing her friend's house in Clapham, south London, at around 9pm on Wednesday and her family say "it is totally out of character for her to disappear like this".
Detective Chief Inspector Katherine Goodwin, who is leading the Metropolitan Police's investigation, provided an update on efforts to find Ms Everard on Monday afternoon.
She said: "This is definitely a missing persons investigation at the moment but I remain open minded as to all possibilities in the investigation."
DCI Goodwin said a hat found as part of the search was not the one Ms Everard was wearing on the night she disappeared.
She said: "We found a hat today as part of one of our searches, we reviewed it and I'm confident that it's not the hat that Sarah was wearing on the night."
DCI Goodwin said specialist officers had been drafted in from across the Metropolitan Police to help with the investigation and she thanked members of the public who had come forward with information.
"We are all looking to try and find Sarah as quickly as possible," she added.
She said she had met Ms Everard's family, adding: "My heart goes out to them in this most difficult time and they are doing everything that they can in order to help find her along with her friends."
DCI Goodwin said search efforts were continuing "at pace".
She said: "We are currently knocking on doors. We've spoken to over 750 different people and addresses have been visited.
"We continue to receive hundreds of calls from the public. We've received over a hundred calls so far."
She said police had reviewed hours of CCTV around Ms Everard's movements on the night she was last seen.
DCI Goodwin also appealed for anyone with more footage to come forward, particularly people with a dash cam, such as delivery drivers, who may have been driving along Poynders Road at around 9pm on Wednesday.
"The evidence that you have on your dash cam could be absolutely vital to finding Sarah," she said.
On Sunday police said detectives had discovered new CCTV of Ms Everard confirming she was walking alone around half an hour after leaving her friend's home.
She left Leathwaite Road at around 9pm on to the A205 South Circular and is thought to have walked through Clapham Common towards her house in Brixton in a journey which should have taken around 50 minutes, Scotland Yard previously said.
A fresh CCTV image - understood to have been discovered on a private doorbell-type camera - captured her walking alone along the A205 Poynders Road, from the junction at Cavendish Road, toward Tulse Hill, which lies just south of Brixton.
It appears to suggest she walked through Clapham Common and was walking towards her home, although the force said it is unclear whether she did return to her house.
The investigation is being led by Scotland Yard's Specialist Crime Command because of the "complex nature" of the case, the Metropolitan Police has said.
Ms Everard was last seen wearing a green rain jacket, navy blue trousers with a white diamond pattern, and turquoise and orange trainers. She is thought to have been wearing green earphones and a white beanie hat.
In an earlier statement, Ms Everard's family said: "With every day that goes by we are getting more worried about Sarah.
"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.
"We are so grateful to the police and all our friends for all they are doing.
"We are desperate for news and if anyone knows anything about what has happened to her, we would urge you to please come forward and speak to the police. No piece of information is too insignificant."
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