Reports from Russia say last week's death of Nauru's transport and health mininster Valdon Dowiyogo was caused by kidney failure.
The minister was in Moscow with his wife for a conference of the UN Economic and Social Commission for Asia and the Pacific when he reportedly fell ill at his hotel.
Emergency services were called to the hotel but according to Moscow police, the minister had died when the ambulance arrived.
According to his wife, he was also suffering from diabetes.
Mr Dowiyogo, who is the son of a former president of Nauru, was 48 years old.