There are grave fears that the Hotel Grand Chancellor building in downtown Christchurch may collapse with reports the building is visibly slumping.

The building is almost warped, witnesses say. It is believed to have sunk three metres in the past 10 minutes.

Meanwhile hopes that 15 people were still alive inside Christchurch's CTV building following yesterday's big quake have been dashed, leaving family members angry and upset.

Police have cordoned off streets in about a four-block radius around the Hotel Grand Chancellor, which is sagging badly and appears to be on the brink of collapse.