The family of a woman missing and feared dead in the Canterbury earthquake has suffered another cruel blow with her home being burgled while her children waited for news.

Producer and presenter Donna Manning is among about the Canterbury Television (CTV) staff missing and feared dead after the regional television channel's building collapsed in Tuesday's 6.3 magnitude earthquake.

Her niece, Lisa Gardiner, said while Ms Manning's two children were down near the collapsed building site yesterday when thieves broke into their family home. The home had been damaged in the quake and they had been unable to shut and lock the doors. There was also no power or water at the house.

Ms Manning's children arrived to find property had been taken from inside the house. They seemed to be holding up well despite this latest blow, Miss Gardiner said.

"It's just so sad," Miss Gardiner said.

"I find it unbelievable that people would do that."

The burglary raises concerns about how many properties are being targeted by thieves as people flee damaged homes or leave the city to escape the ongoing aftershocks.