Three 12-year-old boys made the grim discovery of the body of a newborn baby girl in Rainham on Sunday afternoon.

The tragic tot was found with, but not wearing, a distinctive pink vest from Primark with ‘hug?’ written on it.

The vest can be bought in Europe but not the UK, police said.

The children discovered the newborn in a black bin liner at 4.40pm in undergrowth by the Ingrebourne River, off the A1306 New Road.

Police believe the body may have been there for several weeks.

One possible line of enquiry is that the mum is a frightened youngster who had kept her pregnancy secret before giving birth and dumping the body.

Despite carrying out extensive enquiries, including local door-to-door calls, officers from the Child Abuse Investigation Command have been unable to trace the mother and they are concerned about the mother’s welfare.

Det Insp Colin Welsh said: “The baby was new-born and we are concerned that the mother might need urgent medical attention.

“I would appeal to anyone with information to contact us. The vest inside the bin liner is quite distinctive and I am hoping that someone might recognise it.”

A post-mortem examination which was held at Great Ormond Street Hospital, in central London, was unable to establish a cause of death and further tests are now being conducted.

Officers would also like to hear from anyone who might have seen the bag being left in the undergrowth.

Anyone with information relating to this incident is asked to call: 020 8217 6555 or to remain anonymous, Crimestoppers on: 0800 555 111.