A post-mortem on the newborn baby girl found in a Rainham country park on Sunday has failed to establish how she died.

Further tests are being carried out, a police spokesman said, following the initial examination in Great Ormond Street Hospital, in central London, yesterday (Tuesday).

The tot was found in undergrowth near the Ingrebourne River by members of the public at around 4.30pm.

Officials have so far been unable to tell how old the infant was when she died, nor how long she had been at the scene.

The infant’s ethnicity has not yet been released.

Police teams have been making enquiries at hospitals throughout east London in an attempt to find the mother, who is likely to be in need of medical help.

Specialist teams have spent more than two days conducting a fingertip search of the area around the Ingrebourne, to the back of Rainham Tesco.

A police spokesman said: “The terrain makes searching for evidence very difficult.”

A section of the riverbank remains cordoned off to the public.

Detectives from the Child Abuse Investigation Command are investigating.

Anyone with information should call Crimestoppers on: 0800 555 111.