A mother in India has given birth to a 15-pound baby girl, believed to be the heaviest female infant ever born.

The child weighs the same amount as the average six-month-old and is reportedly twice the size of the average baby.

The baby, who is unnamed, was delivered by cesarean section to her 19-year-old mother, known only as Nandini.

Doctors believe her weight overtakes the alleged current record holder, Carisa Rusack, who was born weighing 14lb 5oz in Massachusetts in 2014.

Dr Venkatesh Raju, the local health officer, said: "In my 25 years of experience, I had never seen such a big baby. 

"She is a miracle. I believe she is not only the heaviest baby born in India but the heaviest baby girl ever born in the world."

Doctors and family were surprised by the size of the baby, because the pregnancy had gone smoothly.

Nandini, the mother, weighs 14.5 stone and is 5'9 tall, and was unaware she was going to give birth to such a large child.

Medics are monitoring the child in an intensive care unit to check her developments, before letting her go in a few days.

The gynaecologist who delivered the baby, Poornima Manu, said: "She came as a big surprise for all of us. The surgery took place for nearly half an hour and it was free of any risk. She is really big and beautiful.

"She does not have any health issues like irregular sugar levels or thyroid and is breathing well. We were initially concerned about her sugar levels but that is normal. 

"The mother had made regular visits for check-ups at the hospital and never showed signs of gestational diabetes or thyroid disorders."

Despite being "big and beautiful", the unnamed baby is far off the current Guinness Record holder for heaviest birth.

This is held by a baby boy born in Italy who was born without any health issues at 22 lb 8 oz to Sig. Carmelina Fedele (Italy) at Aversa, Italy in September 1955.