The body of the girl, who has only been named as Baby M by officers, was discovered at the edge of Manor Park in Aldershot, Hampshire, by a member of local council staff at 1:30pm on 19 May, 2017.
A post-mortem examination has found that the child, who died within a maximum six hours of birth, suffered multiple blunt force injuries to the head with other minor injuries to her body.
Detective Chief Inspector Dave Storey, of Hampshire police, said scientific analysis by the National History Museum identified that the birth would most likely have happened between 6pm on 15 May and 8am the following day.
He said this led to a review of CCTV footage which found images of two people walking past the birth scene in Ash Road 10 times between 11:30pm on 15 May and 12:30am on 16 May.
Mr Storey added that a DNA profile taken from the baby showed that both she and her mother, and probably the child’s father, were of East Asian ethnicity.
He said police were considering that either the mother or someone else was responsible for the injuries suffered. Mr Storey said: “This remains a particularly sad case which despite extensive investigation we are still are nowhere nearer to identifying the newborn baby, Baby M, nor her mother.
“We have a baby who is unnamed and at this stage is still not buried and we would like some assistance in order to identify the mother and obtain some justice for Baby M.”
He added: “Initially when the investigation was launched we were concerned regarding the health of the mother, so there were lots of inquiries undertaken with local partners, NHS and local communities in order to identify the mother which were unsuccessful.
“We have carried out lots of inquiries since then including pathology, scientific work regarding the baby’s ancestry and what was established fairly early on was the baby’s death was a result of deliberate head injuries and as such we launched a murder inquiry.
“We still would like to identify the mother and provide some support because it takes an awful lot for a mother to give birth to a child to then either kill the baby or have the baby taken away from her and killed immediately afterwards.”
Asking for the public’s help, Mr Storey said: “We have a couple walking past the birth scene between 11:30pm and 12:30am and they don’t just walk past once, they walk past 10 times and we strongly believe they may be connected with the birth and subsequent murder and we are appealing for witnesses or information to identify those two persons.
“We are also launching some significant house-to-house inquiries in and around Manor Park to try to identify witnesses or people who have knowledge of the murder.”