Justice Otieno Odek died from blood clot on his right leg.
Chief Govt Pathologist Johansen Oduor said that the clot prevented blood from flowing into his lungs, causing the judge's death.
The three-hour postmortem was conducted at the Aga Khan Hospital morgue in Kisumu.
Oduor was joined by other pathologists, family representatives and Directorate of Criminal Investigations officers to establish what killed the judge.
Justice Odek was found dead at his Milimani home on December 16, 2019 in Kisumu town after he failed to return calls.