Police hunting for missing architect Joanna Yeates are hoping CCTV footage of her buying a pizza will yield clues to her whereabouts.
Officers released some footage of her buying the item in a Tesco Express on the night she was last seen - and it has since become a key part of the investigation.
There was no trace of the pizza, the wrapping or the box in the flat that Miss Yeates shared with her boyfriend - despite the fact that the receipt, the coat she was wearing, and her mobile phone and keys were inside.
The footage shows Miss Yeates, 25, buying the Tesco Finest tomato, mozzarella and basil pesto pizza at around 8.40pm on December 17 in Clifton Village, Bristol.
She is seen using a self-service till in the supermarket and is wearing a cream-coloured coat with a rucksack on her back.
A police spokesman said: "The video has been released by detectives hoping people in the area at the time will remember seeing Joanna and contact the police."
Miss Yeates has not been seen or heard from since last Friday following a night out with work colleagues in Bristol.
Her boyfriend Greg Reardon, 27, reported her missing on Sunday night after returning home to their flat in Canynge Road, Clifton, from a weekend away in Sheffield visiting family.
Detectives are investigating the possibility that Miss Yeates was abducted and said it was one of several lines of inquiry.
Miss Yeates's family are desperately hoping for news with a week having passed since her disappearance.
David and Theresa Yeates sobbed as they acknowledged that she could be being held against her will and begged for her to be returned safe and well.
Mr Yeates, 63, said: "Just let her go. If you have ... if she is dead, then please tell somebody where she is. We want her back whatever."
And he sobbed as he went on: "I was stood outside having a cigarette. It was cold. I was thinking my daughter, maybe she was out there by herself in the snow, frozen. It breaks me up. I want to be there to hold her.
"I've got to believe that she's alive. There's too much life in her. If the inevitable ... if it turns out that she isn't, I still want her back."
Mrs Yeates added in a desperate plea to any abductor: "Just let her go. Let her go, let her come back to me and her dad and her family. Please."
Her daughter was last seen leaving the Ram pub in Park Street at about 8pm, walking up the street.
She popped into a Waitrose on the way - where she was seen on CCTV - rang her best friend to arrange to meet on Christmas Eve and then went to the Tesco Express on Regent Street a quarter of a mile from her flat.
Friends of Miss Yeates have set up the website helpfindjo.wordpress.com/ and an online campaign is running on both Facebook and Twitter.
People have also been putting up posters across Clifton appealing for information.
At a press conference outside the flat where Miss Yeates lived with Mr Reardon, police said they were keeping an open mind over her disappearance.
"There are numerous lines of inquiry at the current time," said Chief Superintendent Jon Stratford, of Avon and Somerset Police.
"What I can say is that we are keeping completely an open mind and we are testing out many different hypotheses. Nothing is being ruled in, nothing is being ruled out.
"We continue to search the area and we have a lot of patrols in the area, speaking to people, providing reassurance and also trying to identify if there are any witnesses we have not spoken to.
"The forensic recovery has come to a conclusion inside the house and detectives continue to do a CCTV trawl of the area."
Mr Stratford said he was unaware of any contact between the detectives investigating Miss Yeates' disappearance and the murder of Melanie Hall in Bath in 1996.
Miss Hall, a blonde 25-year-old university graduate, disappeared following a night out in Bath in June 1996.
Her remains were found at the side of the M5 motorway in October last year. Her killer has never been caught.
"I am not aware of any contact between the two teams and at the current time I am not aware of anything to connect the disappearance of Melanie Hall with this disappearance," Mr Stratford said.
However, Det Chief Insp Gareth Bevan, who appealed for information about the whereabouts of the Tesco pizza, is part of Melanie Hall investigation team and has spoken publicly about that inquiry.
The officer did confirm that the force had spoken to officers leading the inquiry into missing chef Claudia Lawrence in York.
Thirty detectives are working full time on the investigation and are being assisted by another 40 staff, including uniformed officers, forensic experts and search teams.
Anyone who has seen Miss Yeates or knows of her whereabouts is asked to contact the Operation Braid incident room on 0845 456 7000 or Crimestoppers on 0800 555 111.