Ian Rintoul of the Australian Refugee Action Coalition says around 300 people remain on a mass hunger strike.
He says there are unconfirmed reports the medical centre has begun using nastrogastric feeding for some of the hunger strikers, when previously they have relied on glucose drips to rehydrate people.
Mr Rintoul says there are also growing concerns regarding the health of an Iranian man in the 29th day of his hunger strike.
He says the deteriorating situation on Nauru demands that the Australian Minister of Immigration urgently intervene.
Source: The Pacific Islands Report