New Zealand authorities have demolished the Radio Network Building after it was damaged in the Christchurch earthquake during February 2011.

It is the first building in the country to be imploded and the Christchurch Earthquake Recovery Authority plans to bring down other damaged buildings the same way as it is faster and more cost effective than other methods.

Six-year-old Jayden Halliwell, a cancer patient from the city of Queenstown, had the honours of pressing the button to detonate the 63 kilograms of explosives.

The earthquake last year was a magnitude 6.3 and killed 185 people causing extensive damage to New Zealand's second biggest city.