Police have been granted a second extension allowing them more time to question the landlord of Joanna Yeates about her murder.
Former public school teacher Chris Jefferies, 65, was arrested on Thursday in the flat above the one Miss Yeates had rented in Canynge Road, Bristol.
The 25-year-old who was found dead on Christmas Day, had been strangled.
A magistrate granted the custody time limit extension on Friday but the duration is not yet known.
The first extension of 12 hours was granted by a senior officer and was thought to have been due to run out at about 1900 GMT.
Earlier on Friday Avon and Somerset Police revealed a man named as Peter Stanley, who lives next door to Mr Jefferies, was helping detectives with inquiries, that he was being treated as a potential witness and had not been arrested.
He drove away from his home in a BMW with a detective and was later driven back, arriving home just after 1600 GMT in a marked police car.
Police said there had been no forensic examination of his property, adding: "He is helping us with our inquiries."
BBC correspondent Jon Kay said police forensic teams remained at the property on Friday evening.
Miss Yeates's boyfriend Greg Reardon, who lived with her, reported her missing when he returned from visiting family in Sheffield.
The landscape architect's body was found in Longwood Lane, in Failand, near Bristol, by a couple walking their dogs.
Post-mortem tests revealed she had been strangled, police said.
Mr Jefferies, who formerly taught English at the nearby Clifton College public school, lives in the flat above the Victorian basement property he rented to the couple.
He is currently being questioned at a police station within the Avon and Somerset force area after being arrested on suspicion of murder.
On Thursday, officers removed two cars from the street where Miss Yeates lived - a silver Chrysler and a grey Volvo S40.
Miss Yeates's keys, mobile phone, purse and coat had been left behind at her flat and forensic examiners previously said there was no sign of a forced entry or a struggle at the property.
On Wednesday police appealed for information after saying Mr Jefferies had reported seeing three people, one of whom he believed was Miss Yeates, leaving the block of flats on the night she was last seen.
However, later that day he told reporters he denied telling police he saw Miss Yeates leaving with two unidentified people.
Miss Yeates, who is originally from Hampshire, is known to have left the Ram pub, on Park Street, at about 2000 GMT on the night she disappeared.
Police have issued CCTV images of her then visiting a Waitrose store on The Triangle, a Bargain Booze shop, and a Tesco Express near her flat.
She bought a pizza at the Tesco store but while the receipt was found at her flat, no trace has been found of the food or its wrapper.
Crimestoppers has offered a £10,000 reward for information leading to the arrest and conviction of her killer.