Police say the reports show the heart failures of Mark Kennedy and Jeffrey Reynolds were caused by a mixture of heroin and alcohol.
The two men were discovered in their cabin on February 18th while the ship was in port in Port Victoria, Seychelles.
Police found and seized pills, syringes, and traces of heroin from the cabin.
Both men were employed by Trident Security.
The case has now been forwarded to the Attorney General's office for further consultation.