Police have said that more tests are needed to determine the cause of death after two bodies were found on a boat by Wroxham Broad on Thursday.
Post mortem examinations carried out on the bodies of the man in his 60s and woman in her 50s on Tuesday have been inconclusive, police said.
However police are not treating the deaths as suspicious.
The two people and a dog were found dead on a boat moored near Wroxham Island on the River Bure on Thursday afternoon.
Emergency services were called at around 4pm, after someone voiced concerns about the small, white motor cruiser, which had been moored in the same place on the r for a long period of time.
The boat, which is privately owned, was towed away to a nearby boatyard and the seal around the vessel has now been removed.
A spokesperson from Norfolk Police said: 'Officers will prepare a file for the coroner ahead of an inquest which will take place in due course.'
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