Begging on the streets of Auckland is no longer an activity confined to the city's rough sleepers.

MORE: Dame Diane Robertson - Auckland's rough sleepers

The Auckland City Mission estimates at least 40 percent of beggars are people who live in hostels, houses or flatting blocks - any of them beg to cover the rising cost of rent.

Missioner Dame Diane Robertson believes it's an act of desperation by people faced with rising rents they can't afford.

"Because of the cost, mainly of accommodation, they have little money left for the other expenses in their lives," she said.

Dame Diane believes that does not mean the number of rough sleepers is in decline. People sleep wherever they can find a place to stay, and a growing number of families live in cars or vans.

"We see everyday there's more people begging on the street, but there's also more people sleeping rough on the street as well."

Earlier this year, two men dressed as Buddhist monks were warned about begging, after questions were raised about the authenticity of the monks.

Police advised the public to donate to charities, rather than giving money directly to beggars themselves.

Dame Diane said it can be difficult to walk past someone in need, but she said the most effective way to help is to donate to the agencies who work with beggars and rough sleepers.