The pathologist who supervised American researcher Shane Todd's post-mortem examination, carried out one to two days after his body was found, told the court on Thursday that all the evidence pointed to death by hanging and not strangulation.

Senior consultant forensic pathologist Dr Wee Keng Poh of the Health Sciences Authority (HSA) also disagreed with a report commissioned by Dr Todd's parents that found that he had been involved in a fight for his life and was killed by garrotting, which is strangulation by a cord or wire.

He offered alternate explanations for some supposedly suspicious marks found on Dr Todd's body, which included alleged bruises on his hands. He said these were likely due to a process known as post-mortem lividity, which is the pooling of blood that oozes out of blood vessels after death and causes discoloration.

Dr David Richard Fowler, an American chief medical examiner engaged by the state, agreed with Dr Wee's findings and had also said in a report that redness on the back of Dr Todd's neck was likely abrasion caused by the towel found wrapped around his neck. The pattern of the redness matched the weave of the towel, he said.

Three pathologists including Dr Wee and Dr Fowler had said all of the marks on Dr Todd's body was consistent with death by hanging. For example, the mark on his neck was an inverted "V" which is a "classic" mark of hanging. If Dr Todd had been garroted, the mark would have been a horizontal circle encircling whole whole neck.

Instead, there was a gap of 4cm that led up to the noose. There was also no sign of bleeding from broken blood vessels in his eyes, nor was there any bleeding in the internal structures of the neck, both of which would indicate strangulation.