Human remains found in a West Yorkshire river are those of missing Bradford woman Suzanne Blamires, police say.
They were recovered from the River Aire, Shipley, on Tuesday after being found by a member of the public.
A man, thought to be PhD criminology student Stephen Griffiths, 40, is being held on suspicion of murdering Ms Blamires, 36, who was a sex worker.
He is also suspected of killing two other Bradford sex workers, Shelley Armitage, 31, and Susan Rushworth, 43.
A West Yorkshire Police spokesman said: "Examination of human remains recovered from the River Aire have confirmed a positive match to Suzanne Blamires. Inquiries into the incident remain ongoing."
Ms Blamires, who lived in Barkston Walk, Allerton, was last seen on 21 May.
The BBC understands police found further human remains, which have yet to be identified, in the river at lunchtime on Thursday. A coroner's van was seen at the scene.
Detectives have been given extra time, until Thursday evening, to question the suspect.
Mr Griffiths, who lives in a flat in the Holmfield Court building on Thornton Road, was arrested on Monday.
Officers, accompanied by specially-trained sniffer dog teams, have been searching a number of buildings, some of them in the Chain Street area of Bradford's red light district, and underwater search teams have been scouring the river.
CCTV footage is understood to be playing a major part in the police investigation.
Ms Armitage, also from Allerton, has been missing since 26 April and Ms Rushworth, from the Manningham area of the city, has not been seen since June 2009.
Assistant Chief Constable Jawaid Akhtar said it was a painstaking inquiry "with all the necessary resources and expertise devoted to it".
"The families of Suzanne, Shelley and Susan are all being supported by our family liaison officers as the inquiry progresses," he said.
Police started a poster appeal earlier this month to try to trace Ms Armitage - last seen in Rebecca Street in Bradford city centre.
Ms Rushworth, a mother-of-three who is known as Sue or Susie, was last seen near to her flat at Oak Villas, Manningham.
Ms Rushworth's son James, 23, said the family had been growing increasingly concerned for her welfare.