Prince Charles expressed shock on Friday at the devastation that still scars Christchurch, the New Zealand city rocked by an earthquake last year that claimed 185 lives.

On the final day of a Pacific tour marking Queen Elizabeth II's diamond jubilee, Charles and his wife Camilla visited the South Island city's "red zone", the downtown area that bore the brunt of the quake on February 22, 2011.

Prime Minister John Key showed the royal couple around the ruins of his hometown, where shattered office blocks are still being demolished as part of a NZ$30 billion ($24.3 billion) reconstruction.

"They've been really touched," Key told reporters. "I was in the van with them and they were shocked at the devastation and the experiences meeting the victims of the quake."

Charles had a private meeting with around 20 people who were seriously injured in the quake and he also visited damaged homes, which residents are still trying to rebuild.

But there were lighter moments too as the royals were greeted by thousands of well-wishers at Cashel Mall, a shopping precinct that has been temporarily rebuilt using brightly-coloured shipping containers to house its stores.

"We only really came here for the beer," Charles joked with one onlooker.

The couple also went for a twirl on the city's "dance-o-mat", a makeshift outdoor dance space created after most venues were destroyed in last year's disaster.

Local resident Lisa Shannon coaxed Charles onto the dance-floor, while Sam Johnson, who used social media to organise a post-quake clean-up group called the Student Volunteer Army, went for a spin with Camilla.

Johnson said it was a welcome moment of levity in the city.

"It shows we're going through a new phase -- we're celebrating the small things as we're going through the rebuild," he said.

"Asking the Duchess of Cornwall to dance was a bit unexpected but I thought 'why not?'."

The royal couple will depart Christchurch for Britain later on Friday, marking the end of a two-week trip that also took in Papua New Guinea and Australia.