Wellington, Sept 8 NZPA - A strong smell of sulphur spreading across Christchurch's eastern suburbs is unlikely to be gas, Civil Defence says.

New Brighton resident David Shone told WeatherWatch that people noticed the smell after Saturday's devastating 7.1 magnitude quake, saying it smelt similar to Rotorua.

The smell was today investigated by the Fire Service and Environment Canterbury's hazardous substance team.

"At this point, there is no indication that the smell should be of concern to residents. It does not appear to be a gas leak," Canterbury Civil Defence emergency management group said.