It's been revealed that a typical grocery shop in Auckland is twice as expensive right now than it is in London.

New Zealand food prices this week came under scrutiny after a photo posted on the Kiwis in Aussie Facebook page showed kumara cost nearly 11 times more here.

That difference was blamed on population size, wet weather and growing export markets in Asia and the East.

Focus reporter Brigitte Purcell carried out a supermarket shop in London, while Focus reporter Carla Penman took that same list to an Auckland supermarket.

Warning: Results may startle some New Zealanders.