A newborn baby found abandoned by dog walkers was not stillborn, police have revealed.
Detectives believe the girl, given the name Alia, lived for a short period of time after her birth.
They have released images of items which were recovered along with her body in the hope of tracing her parents.
The child was discovered shortly before 4.55pm on Thursday March 14 in Ox Hey Lane, Lostock, near Bolton, by a man and woman out walking their dog.
She had been wrapped in clothing and placed inside a plastic bag, and there was a message requesting that she receive an Islamic burial.
Following discussions with the Bolton Council of Mosques, detectives named her Alia, meaning beautiful.
A specialist neonatologist has established that she was born alive and lived independently of her mother for up to two hours.
However, the cause of her death has yet to be established, as does her ethnicity.
Three items recovered along with her body included a Tesco bag, with the words "Please please bury him Islamic way please please" written on it in English
It is believed baby Alia was wrapped in a white shirt and cotton trousers and placed in this bag, which was in turn placed in a JD Sports bag.
A pair of three-quarter length, paint-stained cotton trousers were also found at the scene.
Detective Inspector Aaron Duggan, from Greater Manchester Police , said: "Despite the passage of time, our primary concern still remains the welfare of baby Alia's parents, in particular her mother.
"She was found almost six weeks ago and we still need to make sure both mum and dad are OK, both physically and mentally.
"This will have been a traumatic experience for them, particularly if they are young."
DI Duggan added: "What we don't know, and what we are trying to establish, is how, where and when she died and when she was placed at Ox Hey Lane and by whom.
"I want people to think about someone that perhaps they knew or suspected was, up until recently, pregnant and, coupled with these images, now think they know who the mother or father is and to call us in confidence.
"I want to appeal to the parents directly to come forward, to talk to us and explain what happened to their daughter. I want to reassure them that specialist help is still available if required."
Anyone with information is asked to call police on 0161 856 5448, or Crimestoppers, anonymously, on 0800 555 111.