Investigators believe the mother of a baby girl whose body was found at a recycling plant may have had a “difficult labour” - but key questions remain unanswered.
The tiny body was found wrapped in a pink beach towel over a year ago but the parent has never been traced.
Detectives have followed up “numerous” leads but are no closer to unravelling the mystery.
The full-term baby was found on a conveyor belt by worker Adam Ferguson at the Bradford Council waste recycling facility on Bowling Back Lane on August 20 last year.
An inquest was told the girl was fair-skinned and had a full head of brown hair. She had suffered injuries that were deemed to be consistent with having been in a bin lorry.
Post mortem examinations by pathologists Professor Marta Cohen and Dr Kirsten Hope had concluded that the cause of the baby's death could not be ascertained, YorkshireLive reports.
They said that the child had "potentially drawn breath" but it was not possible to say whether this happened during or after she was delivered.
Tests also revealed a genetic abnormality of the heart but the pathologists concluded it wasn't possible to draw further conclusions about its effects.
Detective Sergeant Daniel Townend, of West Yorkshire Police's Homicide and Major Enquiry Team, said extensive inquiries had been carried out in an effort to trace the mother but to no avail.
DNA testing has been carried out on the towel and police remain concerned about the welfare of the mother.
Checks had been made on vulnerable mothers and discussions had taken place between police and midwifery teams but “numerous names” had been ruled out.
Det Sgt Townend said a leaflet drop had been carried out in two areas of Bradford where two big wagons had visited before calling at the depot, yet no names had been put forward.
It was not possible to narrow waste collection points any further.
In a narrative verdict, assistant coroner Angela Brocklehurst said the evidence in the case was limited to the circumstances around the discovery of the child and medical details relating to possible causes of death.
She said: "No evidence has been discovered as to the date and time and place of the child's real death, therefore those questions remain to be answered.
"The medical evidence we have fails to answer the questions how and by what means did this child come by her death, in one way or another, or not."
She said evidence had been heard about whether the child had been able to draw a breath but concluded: "Sadly, in the absence of a placenta, despite searches being made, neither pathologist has been able to determine an answer to that question or determine at what point the child's life came to an end and for what reason."
The coroner said DNA samples of the child had been extracted and kept for future reference, adding: "The only facts arising from the evidence are that an unidentified child has died at an unknown time and place from an unknown medical cause of death."
She thanked West Yorkshire Police and the two pathologists for their extensive work on the case.
