Fire Service special operations national manager Jim Stuart-Black earlier said someone appeared to be alive in one of the buildings in the central city.
Newstalk ZB reported that rescuers had made contact with a survivor trapped in the rubble of the Holy Cross Chapel on Chancery Lane.
A Fire Service spokeswoman said search and rescue teams with dogs had done a full investigation and been unable to find any signs of life at two buildings on Chancery Lane and Gloucester St.
One of those buildings is thought to be the Holy Chapel Chapel, where it is estimated more than 20 people remain trapped.
Police earlier said no more survivors had been pulled out of the rubble overnight, with the last person rescued alive at 3pm yesterday.
Searchers are still looking for survivors trapped in pockets of the devastated Canterbury TV and Pyne Gould Corporation buildings.
So far, 60 percent of the central city had been cleared by Urban Search and Rescue, Mr Stuart-Black said.
"The remaining 40 percent, we have got some difficult areas to clear."
The confirmed city-wide toll from Tuesday's lunchtime 6.3-magnitude quake was lowered overnight from 75, to 71 but with hundreds still missing, police expect that figure to climb dramatically.
No survivors have been found since yesterday afternoon.
"We are still looking for survivors," Superintendent Russell Gibson said this morning after reports that rescuers were now looking for bodies rather than survivors.
"Experts tell me there are pockets within a number of these buildings and provided people haven't been crushed there is no reason to expect that we will not continue to get survivors out of there," he said
Yesterday the CTV building was declared "unsurvivable", with between 50 and 100 people still trapped inside.
Rescue work at the site was halted by safety concerns as the nearby Hotel Grand Chancellor threatened to collapse.
Fifteen CTV staff, four Filipino nurses and a number of Japanese students from a foreign language school that operated in the building are believed to be among those inside.
Mr Gibson said no survivors had made it out the CTV building since 3pm yesterday but he still had hope.
"It doesn't look good but we are always hopeful, we will continue to pull that building apart piece by piece until we are satisfied," he said.
Civil Defence Minister John Carter said this morning police were currently reviewing the number of people missing.
Rescuers were focusing their attention on four main buildings where they thought there might be survivors, he said.
But as international help arrived the rescue area was being widened to spread right across the city.
So far, 431 people had gone through the Emergency Department and 164 patients had been admitted as "seriously injured", Mr Carter said.
About 20 people are thought to remain in the pancaked PGC building.
Meanwhile, the 70m-high Hotel Grand Chancellor, one of the city's tallest buildings, remained standing overnight, despite a number of aftershocks, including a 4.1 magnitude shake just after midnight.
Reports yesterday said the hotel had slumped in one corner, prompting fears that should it collapse it could destroy surrounding buildings.
Twenty-two people are believed by police to have died in the collapse of ChristChurch Cathedral. Police dogs had been through the area of the 130-year-old city landmark and police were confident there were no survivors there.
Overnight 190 police officers enforced a central city curfew and it was quiet apart from rescue efforts, police spokeswoman Sarah Kennett told NZPA.
Yesterday there were six arrests for looting.
Search and rescue teams from Taiwan and Singapore arrived last night and joined Australians already on the ground today. US and UK teams are due to arrive today.
Overnight the Pope and the Dalai Lama extended their sympathy to the quake victims, joining other world leaders such as the Queen and US President Barack Obama offering their condolences.
The Government yesterday declared a national state of emergency for the first time, following what Prime Minister John Key described as the "death and destruction on a dreadful scale" of the quake.
Mr Key said Cabinet would today discuss funding strategies for quake-affected people, and as with the September 4 quake, some sort of package was likely to be brought in.
The Crusaders have decided to withdraw from this Saturday's game against the Hurricanes in Wellington, saying it was inappropriate in the wake of such a disaster.
