A newborn baby girl found dead in a plastic bag near a river had suffered several serious injuries, including a fractured skull and collarbone, police said today.
Detectives investigating the unlawful killing of the child, named Lilly by officers, also revealed details about clothing and other items found with her body.
These included four bloodstained tea towels found inside a Tesco carrier bag which was concealed inside a Mothercare bag, as well as a pair of women's pyjama bottoms.
Detective Chief Inspector Adrian Pearson told a press conference in Stratford-upon-Avon that officers were still attempting to trace the mother of the baby, whose body was found at Aston Cantlow, Warwickshire, on May 11.
"Baby Lilly has a family, she has a mum, a dad, grandparents, brothers and sisters perhaps," the officer said. "We need to know her background and how she came to lose her life in such tragic circumstances."
Mr Pearson also issued an artist's impression of the child's face, although her ethnicity has not been established.
Tests carried out on the full-term baby revealed she was healthy in every other way beside the injuries which caused her death, which were not consistent with childbirth.
Mr Pearson said the fractures had been inflicted on the child very soon after her birth.
The body - found beside the River Alne by a family out walking - had been dumped at the site no more than two days before it was discovered.
Mr Pearson told reporters: "We are appealing now to the public to identify Lilly and find out exactly why it was she lost her life.
"Mum has left us a big bag of clues. I am certain people today who hear this message will be able to put these together and identify Lilly for us."
Mr Pearson said he remained open-minded about whether the number of clues left at the scene amounted to a cry for help from the mother.
He said it was possible she was in an abusive situation and afraid to come forward but had left enough information about herself to be traced.
The pyjama bottoms found at the scene, replicas of which were on display at the press conference, were size 12 to 14, and sold by British Home Stores in 2002.
Mr Pearson said they were well worn and appealed to anyone who knew the whereabouts of the matching top to come forward.
Also found in the bag were a pair of women's knickers, size 12, a dish cloth and two black socks.
A turquoise navel ring was found in a nearby lay-by and shards of plastic discovered close to the scene.
Mr Pearson said he was keen to establish who these items belonged to and why they were there, to eliminate the owners from his inquiry.
He appealed to anyone with information which could help police to contact the incident room on 01789 444693.