A baby has been born 'pregnant' with his own twin brother.

A ‘pregnant’ baby has reportedly been born with his twin growing inside him.

Doctors discovered the half-formed twin sitting behind the unnamed newborn’s stomach upon delivery in India, The Independent reports.

The ‘twin’ was a male baby measuring 7cm, with legs, one arm and a brain but no skull. It was removed safely and the newborn baby is otherwise healthy.

The radiologist picked up on the abnormality inside the foetus during a routine scan before the newborn’s birth.

The newborn and his ‘twin’ were born to a 19-year-old mother in India as a case of foetus in foetu.

The condition is a rare congenital deformity resulting in the parasitic foetus growing within the body of the baby.

Foetus in foetu occurs in one in every 500,000 births, but ABC reports there is thought to be less than 100 cases documented around the world.

A similar case occurred in March in Indonesia, when a 10-month-0ld boy’s swollen stomach was found to be carrying his twin.