A teenage boy in Malaysia has undergone an abdominal surgery to remove the foetus of his unborn twin which had been carrying for 15 years.

This phenomenon occurs in 1 in every 500,000 live births and is medically known as “foetus in foetu”, which means that 15-year-old Mohd Zul Shahril Saidin had been carrying the growing foetus since birth.

The foetus had hair, legs, hands and genitals.

Mohd Zul Shahril was only hospitalised recently after he began complaining of pain in the last four months, as Mirror reports.

The boy is still recovering in hospital.