The uncle of missing Sarah Everard has told Sky News the family is "distraught" following the arrest of a police officer over her disappearance.
Nick Everard said "things are utterly dire", but they were hoping and "waiting for positive news from the police".
The Metropolitan Police said officers are searching a number of locations in Kent but have not revealed where.
Sky News understands a police search is taking place in woodland near Ashford, Kent, but it has not been confirmed if this is linked to the case.
A property in Deal is also reportedly being searched and a car was seen being taken away from the property. A neighbour said police were also digging up the garden.
Mr Everard's comments come after Scotland Yard said investigators "really hope" the 33-year-old is still alive.
A serving Metropolitan Police officer was arrested last night in connection with Ms Everard's disappearance.
The officer, who was not on duty at the time of Ms Everard's disappearance, was arrested at an address in Kent.
A woman was also taken into custody and is being held at a London police station on suspicion of assisting an offender.
The force has not said what the officer was arrested for, and Mr Ephgrave would not say whether the person knows Ms Everard.
Earlier, Assistant Commissioner Nick Ephgrave said: "This is a serious and significant development in our search for Sarah and the fact that the man who has been arrested is a serving Metropolitan Police officer is both shocking and deeply disturbing."
He told reporters that detectives are working "at all speed" to find out what has happened to Ms Everard, and repeated appeals for members of the public to come forward with information.
He added: "As a father myself of four young women I can only imagine the anguish that Sarah's family are feeling at this very very difficult time."
Ms Everard's family and her friends have issued desperate appeals for help via social media.
On Monday, Mr Everard said her phone was not ringing and WhatsApp messages were not getting through.
He said his brother and sister-in-law are "beside themselves with worry" and pleaded with anyone who may be holding his niece to "just be human and to let her come home".
"Let her talk to us, give us a ring or text to let us know she is OK," Mr Everard added.
Ms Everard's parents and brother and sister have joined the search for her in Clapham, south London, and have been walking her last known journey, he told The Sun.
She went missing while walking to her home in Brixton from the nearby Clapham Junction area on Wednesday evening.
Ms Everard had been at a friend's house when she left the property in Leathwaite Road around 9pm.
The marketing executive has not been seen or heard from since.
Anyone who has seen Ms Everard or who has information that may assist the investigation should call the Incident Room on 0208 785 8244