A jumbled collection of posters, a bashed old barbecue table and chairs, YouTube clips, lamps and a paranoid handwritten note has won the Walters Prize, the richest contemporary art prize in the country.

Auckland artist Dan Arps' Explaining Things was awarded the $50,000 prize, which includes a New York residency, for his seemingly random installation of dumped domestic objects.

The biennial prize was presented to Arps, 34, by international judge, former Tate Modern director Vicente Todoli, of Spain, at a function at the Langham Hotel.

"[Dan Arps] has transformed these found materials through his own editing ... and has taken them into another, higher realm ... turning Explaining Things into a revelatory multi-layered expereince," said Mr Todoli.

Arps and his three fellow contenders - Fiona Connor, Saskia Leek and Alex Monteith - were the youngest group of finalists for the Walters since its debut in 2002.

The prize, established to honour the late artist Gordon Walters, is privately funded by benefactors who include Mrs Dayle Mace, Erika and Robin Congreve and Dame Jenny Gibbs, in partnership with Saatchi & Saatchi, Ernst & Young, and Auckland Art Gallery.

Arps said in an earlier interview with the Herald that Explaining Things, first shown in 2008 at Gambia Castle gallery in Karangahape Rd, was "an uncharacteristically minimal show for me".

Arts commentator Warwick Brown has described Arps' installation as "displayed in an exceptionally casual manner".

Previous winners are Yvonne Todd, the et.al collective, Francis Upritchard and Peter Robinson.

The works by all four finalists are on show at the New Gallery until the end of the month.