Senior deputy public prosecutor Datuk Kevin Morais might have been smothered to death, the High Court was told here today.

Kuala Lumpur Hospital forensics medical consultant Dr Nurliza Abdullah, 51, said this was based on the conditions of a victim who suffered from asphyxiation.

"In such a condition, his head could have been tightly wrapped with a plastic bag, causing the victim to suffocate.

"In another condition, the victim could have been compressed on the chest which showed signs of swelling to prevent breathing movements," she said in a cross-examination by counsel Datuk N. Sivananthan on the fifth day of hearing in the murder trial of the deputy public prosecutor.

Asked to comment on other sources of asphyxiation, Dr Nurliza said: "I am of the view that a combination of all these methods caused the victim to suffocate."

READ: Kevin Morais did not handle 1MDB case

READ: 'Charles Suresh is a coward' - IGP

Apart from that, she said Morais died of suffocation from an unnatural cause.

She said there were many causes of asphyxiation but suffocation referred to unnatural causes.

"In pathological forensic understanding, the word 'natural' in natural condition refers to illness suffered by a person.

"Unnatural causes refer to external factors not related to sickness which cause asphyxiation," she said.

Replying to a question by Sivananthan on how she confirmed the death was due to unnatural causes, Dr Nurliza clarified as the person who conducted the post-mortem, she would conduct a thorough examination and linked conditions to the death of a person.

Sivananthan however, questioned the phrase, "most probably attributable to asphyxiation suffocation," used in Dr Nurliza's post-mortem report dated Oct 22, 2015, on the cause of Morais' death.

Sivananthan: Why could not you just say the cause of death is asphyxiation suffocation?

Dr Nurliza: As mentioned, the body was already in the process of decomposing.

Sivananthan: Because of the condition of the body, you could not say with certainty, that the cause of death was asphyxiation suffocation. That is why you used the word, 'probably'?

Dr Nurliza: I disagree.

Sivananthan: Do you agree, in other words, we are here with a post-mortem report that is based on high probability?

Dr Nurliza: That is what I meant, a high probability. To me, it is reasonable medical certainty.

She again clarified that Morais' body was not in fresh condition in which all signs of asphyxiation were visible.

"I also exempted the other causes of death such as sharp force injuries, projectile-induced injuries, heat-radiated injuries as well as signs of broken bones on the body as there was no sign of internal bleeding in the body," she said.

Dr Nurliza also denied Morais died from heart failure as a person who experienced heart failure due to the lack of blood flow, and not due to asphyxiation.

Six men - G. Gunasekaran, 48, R. Dinishwaran, 24, A. K. Thinesh Kumar, 23, M. Vishwanath, 26, S. Nimalan, 23, and S. Ravi Chandaran, 45, pleaded not guilty to murdering Morais between 7am and 8pm on Sept 4, 2015 between Jalan Dutamas Raya Sentul and No: 1, Jalan USJ1/6D, Subang Jaya.

READ: Prosecution will prove involvement of seven men in the murder of Kevin Morais

Col Dr R. Kunaseegaran, 53, the primary accused, pleaded not guilty to the charge of abetting the six men in the murder at the same place, date and time.

Hearing before Justice Datuk Azman Abdullah resumes tomorrow.