Two people are being questioned after a seriously-injured baby was discovered at the base of a 50ft rubbish chute.
Officers found the girl, thought to be only days old, in a waste collection area at the foot of a block of flats in Wolverhampton city centre on Sunday night.
She was taken to Birmingham Children's Hospital and is said to be in a critical condition.
Officers have been given a further 36 hours to interview a 24-year-old woman and a 32-year-old man arrested at the 10-storey block of flats in Boscobel Crescent.
The woman is being held on suspicion of attempted murder, while the man is suspected of assisting an offender.
Residents at the flats told The Daily Telegraph the infant had fallen down a chute, which was accessible on the fifth floor landing.
Nora Donnelly, 49, said: "There were about five police cars and two ambulances at the front door. You could hear a child crying in the back of one of the ambulances.
"People were saying that a baby girl from the fifth floor had gone down the chute.
"It's strange because I don't remember seeing anyone pregnant or carrying a young child around.
"It's a real shock to have something like that happen around here - I don't know who could do that to a baby. I just hope she's going to be all right."
Detective Inspector John Smith, from West Midlands Police, said: "We are making a number of inquiries to establish how this young baby has come to sustain her injuries, and how she came to be found in the refuse area of the flats.
"The two people who have been arrested are related to the baby and we are currently not seeking anyone else as part of our inquiries.
"We urge anyone who has information to help our investigation to come forward at the earliest opportunity."
