A doctor who specialises in treating injuries from childhood abuse has admitted she has never seen injuries like the ones suffered by the ten-month old boy allegedly murdered by Mervyn Bell.
Mr Bell has pleaded not guilty to murdering and sexually assaulting the baby after taking him from Broome on March 19, 2013.
The 10-month-old baby had suffered horrific injuries from head to toe, including a broken arm and leg and burns on his feet, legs and body.
The boy also had severe injuries to his genitals and anus.
Dr Louise Houliston, from the child protection unit at Princess Margaret Hospital, observed the post-mortem of the infant, and was called to give evidence about the scope and possible cause of his injuries.
Dr Houliston said it appeared some of the brushing and cuts to the boy's face and body appeared to have been caused by being struck by an implement.
And the doctor said she had never seen an injury the size of the massive graze which appeared down the entire length of one of the boy's legs.
Dr Houliston said a triangular wound on the base of one of his feet was "incredibly unusual and very suspicious".
Mr Bell has denied killing the boy, claiming he fell out of his car as he drove about 60km/h out of Broome.
Despite admitting the baby appeared "pretty banged up", he claimed he did not want to take him immediately to hospital.
Instead he kept driving, stopping at various fishing holes where he claimed he had washed the infant to cool him down.
He then said that at one of these pools, the baby had ended up face down in the water after slipping from between his legs.
CCTV footage of Mr Bell stopping at Coles in Karratha and a nearby liquor store in the hours before the baby's death have also been shown in court.
The trial continues.