The biggest ever art auction is happening this weekend. 

We're talking about the BNZ Art Collection, which features works from some of our best known artists including Rita Angus, Gordon Walters and Colin McCahon whose piece 'O let us weep' could fetch as much as $2 million.

The proceeds of the auction will go towards a philanthropic foundation designed to help organisations create better a better future for our communities - Webb's Auction House Director of Art Charles Ninow joined Mike Hosking.

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