Detectives have been granted extra time to question a 32-year-old man who was arrested on suspicion of the murder of landscape architect Joanna Yeates.
The suspect was detained in the early hours of Thursday morning after police investigating the 25-year-old's death uncovered fresh evidence.
Soon afterwards, specialist search teams moved into a neighbouring flat in the building where Miss Yeates lived at 44 Canynge Road, Clifton, Bristol.
Dutch engineer Vincent Tabak, 32, is registered as living at the address with his girlfriend Tanja Morson.
An Avon and Somerset Police spokeswoman said: "Police have this morning been granted extra time to question a 32-year-old man arrested yesterday on suspicion of the murder of Jo Yeates."
Police officers were seen at the offices of Tabak's employer, international consultancy Buro Happold, in Lower Bristol Road, Bath.
The firm, and several colleagues, referred all inquiries to Avon and Somerset Police. The force has not named the suspect in custody.
The early-morning arrest is believed to have taken place at a converted Victorian terrace house in Aberdeen Road, Clifton.
Later, forensic officers loaded three wheelie bins and a mountain bike from the address in Aberdeen Road into an unmarked white Transit van.
Miss Yeates's father welcomed the latest development, which comes almost five weeks after his daughter disappeared.
Speaking at the family home in Ampfield, Hants, David Yeates, 63, said on Thursday that he was "pleased" the police investigation was "moving forward".
He said: "We know as much as you do. We were told at 6am this morning that someone was arrested on suspicion of Jo's murder and their age."
Detective Chief Inspector Phil Jones, who is leading the inquiry, thanked Miss Yeates's family and boyfriend for their support.
He said: "I would like to thank the public for their continued support for the investigation and the information they have provided to us."