Hockney met the sitter while painting her pool for his California Dreaming series
A classic painting by David Hockney has gone on display in the UK for the first time in 20 years.
The painter's Beverly Hills Housewife can be seen at Christie's of London before a 13 May auction in New York.
The 1960s work depicts and was owned by American collector Betty Freeman. It is part of a collection being sold following her death in January.
Christie's expects the painting to sell for between £5m and £7m, which would be the most ever paid for a Hockney work.
The Splash, another painting from the Yorkshire artist's Los Angeles period, sold for £2.6m in 2006.
Beverly Hills Housewife measures 12ft by 6ft (3.7m x 1.8m) and stretches over two canvases. It was last on display in the UK in 1988 - 89 when it formed part of a Hockney retrospective at the Tate gallery.