Police have confirmed they are investigating claims murder victim Joanna Yeates was outside her flat with two people on the night she vanished.
The landlord of the property in Bristol has told detectives he saw three people leaving and believes one of them was 25-year-old Miss Yeates.
Crimestoppers has offered a £10,000 reward for information leading to the arrest and conviction of her killer.
Miss Yeates' body was discovered on Christmas Day. She had been strangled.
The discovery was made in Longwood Lane, in Failand near Bristol, by a couple walking their dogs.
Det Ch Insp Phil Jones said: "There are a number of lines of enquiry we are following up.
"One of these concerns apparent reports that several people were seen or heard in or around Joanna's flat on the night of her disappearance."
'No forced entry'
Officers have also removed the front door to Miss Yeates' flat in Canynge Road as part of the investigation.
A police spokeswoman said: "The door is being taken for forensic analysis."
Miss Yeates' was last seen alive on 17 December.
She is believed to have returned to the flat she shared with her boyfriend Greg Reardon in the Clifton area of the city after an evening at the Bristol Ram pub, on Park Street.
Her keys, mobile phone, purse and coat had been left behind at their flat and forensic examiners have said there was no sign of a forced entry or a struggle at the property.
Mr Reardon reported her missing to police on 19 December when he returned home from a weekend visiting family in Sheffield.
Police have now issued CCTV images of Miss Yeates at a Bargain Booze shop in Clifton where she bought two bottles of cider on the night she disappeared.
The bottles - one of them half drunk - were found in her flat.
Images of her visiting a Waitrose store and a Tesco Express store in Clifton, after leaving the Bristol Ram have already been released.
Mr Jones said: "We know that there were a number of people in the Canynge Road area on the night of Joanna's disappearance.
"We want to hear from any of these people or anyone else with information that can help the enquiry.
"We have, of course, been keeping in contact with Joanna's family and keeping them informed of our progress.
"Late last night, I received a message from Mr Yeates in which he stated he and his family had "total confidence".
"Indeed, Mr Yeates said 'we truly believe that you will identify the person who killed our daughter'.
"I am, of course, grateful to have the support of the family.
"They, and the general public, can rest assured that myself and my team will leave absolutely no stone unturned in our attempts to find whoever killed Joanna and to bring them to justice."
Police have said post-mortem results showed she had been dead for "several days before being discovered".
They are now trying to fill in the gaps between her disappearance and Christmas Day when her body was discovered.
Officers particularly want to hear from anyone who saw anything suspicious around the entrance to Durnford Quarry, close to where she was found, between 17 and 19 December.