Urban Search and Rescue (USAR) spokesman Paul Baxter today told a media briefing crews had completed their operation at the site, and were now focused on the Forsyth Barr building.
The quake death toll was lifted by one to 166 today, and police believe it could exceed 200.
The estimated death toll was revised down after police yesterday announced that no bodies were found in the rubble of the iconic ChristChurch Cathedral, where up to 22 people were thought to have been crushed.
Mr Baxter would not rule out the possibility of finding victims in the Forsyth Barr building.
He said a search dog had earlier indicated there were victims beneath the rubble, but had since been back and found no trace.
Superintendent Sam Hoyle said today it could take months before all victims recovered are identified.
"No one is more aware than the DVI (Disaster Victim Identification) team that many families are waiting for their loved ones to be returned to them, especially those who are our guests from overseas.
"We know the wait is difficult, but we absolutely must get this right."
He said the "severe nature of the injuries" meant some families may never recover the bodies of loved ones.
Police closely monitored several Christchurch suburbs overnight as surface flooding made some roads impassable in Bromley, Avondale, St Martins and Dallington but admitted a high tide point after 6am had passed without incident.
Mr Hoyle this morning reiterated calls for drivers to be cautious as the surface flooding receded.
People's nerves were again tested last night as residents suffered through seven more big tremors in about three and a half hours.
A magnitude 4.8 aftershock at 7.34pm was the biggest since the February's magnitude 6.3 tremor - sharp enough to unsettle many residents, whose nerves have already been frayed by all the death, destruction and frequent aftershocks.
Fire crews were busy following the aftershock, with people calling for help because of chimneys.
"They were are dealt quite easily by our staff," Mr Baxter said.
Despite the rain and aftershocks overnight, Christchurch City Council went ahead with plans to lift the cordon in parts of the central city this morning.
The city has been divided into four green zones where restricted access will be allowed, and a red zone closed to the public.
Zones one and two to the east and west of the city centre were opened to residents, business owners and property owners with photo identification and proof of address at 8am.
A line of more than 50 cars stretched along the Moorhouse Avenue access point as people waited to get the first public access inside the cordon.
Resident and apartment block owner Anne Marshall had been back to her home since the quake, but was still nervous to return.
"We already saw the place all smashed up, but it's still not a nice feeling going back," she told NZPA.
"It's heartbreaking. It's our home; it's our business; it's everything."
The general public may collect cars parked in these zones from 2pm.
Access to zones three and four to the north, and the central red zone where recovery efforts continue, remain restricted.
The council is looking into how vehicles will be removed from these zones, with a plan expected Tuesday.
Mayor Bob Parker said 95 percent of the city now had power, and 81 percent have water.
