A 95-year-old woman injured in Greece's deadliest fire last month died this morning, raising the death toll to 91.

The woman succumbed to burn injuries hours after the government, widely criticised for its response to the emergency, replaced the heads of the police and fire brigade.

The minister responsible for the police and state security also quit last week.

Another 36 people are still hospitalised after the 23 July disaster, six of them in critical condition.

Irish man Brian O'Callaghan-Westropp was among those to die in the fire as he celebrated his honeymoon in the area.

Opposition parties have accused the government of failing to provide adequate warning and evacuate the coastal resort of Mati which had been frequently hit by wildfires, in addition to subsequently trying to hide the scale of the loss of human life as the disaster unfolded.

The fires burned with such ferocity that most people fled to the sea with just the clothes on their backs.

In the days that followed, the firefighters and police issued conflicting announcements over what went wrong.

One police union this week said the fire department officers had not promptly notified police of the fire's exact location so they could set up proper roadblocks in the area.

As a result, many drivers were mistakenly diverted into the fire zone and died after becoming trapped in Mati's narrow streets.

The government had insisted that with winds blowing at speeds of up to 120km/h, there was little time to mount an effective evacuation.

Officials also said that decades of illegal construction in the area had blocked escape roads to the coast. 

The environment ministry has now pledged to tear down illegal buildings - permitted by successive administrations to remain standing in return for fines and possible votes - in Mati and other fire-prone areas.