Unsafe gas levels were detected in the bathroom of a Sydney Harbour cruise ship where a woman's body was found at the weekend.
The 39-year-old woman was found unconscious about 4pm on Saturday in the bathroom of the Lady Rose - a three-level vessel owned by All Occasion Cruises.
The woman was unable to be revived.
Australian Maritime Safety Authority, whose officers boarded the vessel on Monday, are investigating the incident alongside police and Fire and Rescue NSW.
Police say several detection tests conducted in the bathroom found gas levels in excess of safe operating levels.
It's believed the Berowra woman collapsed in the bathroom where passengers on the boat had reported a "strange smell".
Further forensic testing is expected to take place on the vessel which is now secured at the Sydney water police headquarters at Balmain.
AMSA is investigating if any federal marine safety laws have been breached, a spokeswoman told AAP on Monday.
The death is not believed to be suspicious or drug-related, police said.
All Occasion Cruises has been contacted for comment.
