You've probably heard of illicit hooch being brewed up in prisons but what about unlawful yoghurt?
From secretive beginnings in a cell in Rangipo Prison, two inmates got so good at making the dairy product, it was smuggled to prisoners across the country.
The original recipe was inspired by an episode of the English cooking show, The River Cottage.
Now, with a little RNZ help, host Hugh Fearnley-Whittingstall has met the former meth addicts who became known as 'The Yoghurt Mafia'.
Eva Corlett with this story of an unexpected prison culture.