A recently discovered painting by British artist LS Lowry has sold for more than STG2.65 million ($A5 million) after 70 years in the hands of one of the pioneers of DNA research.
The Mill, Pendlebury depicts an industrial landscape in the northwest of England and was painted by Lowry in 1943.
Like the majority of Lowry's work, it is inspired by the mills, factories, chimney stacks and bustle of the country's industrial heartlands.
But it features clearly defined figures of families enjoying a day out, instead of the hoards of vaguer "matchstick" men in the shadow of the urban landscape that recur in many of his paintings.
The art world was unaware of the painting's existence until the death of Manchester-born scientist Dr Leonard D Hamilton in August last year.
Hamilton bought the painting in the early stages of Lowry's career and hung it in his room while studying medicine at the University of Oxford.
He took it with him when he moved to the US in 1949, where he went on to make a major contribution to the discovery of the double helix shape of DNA.
The painting was sold to a private collector for STG2.65 million on Tuesday evening at London auction house Christies.
Nick Orchard, head of Modern British Art at Christies, said the composition of the painting "just ticks all the boxes".
"The figures are a lot more differentiated than in other works, although it is not untypical from Lowry's work from this period, but the figures add the emotion to the painting.
"It's about the people and their ease in an industrial setting. It's a happy painting - it has to be a Saturday or a Sunday because the men are not at work, they're pushing the prams.
"The children are not at school, they're playing cricket."
He added: "It's Britain at play, which is a nice thing to see."
Mr Orchard said the painting's history would also have been a draw for collectors.
While working at the Sloan Kettering Institute in New York, Mr Hamilton developed a technique for extracting DNA.
The rich DNA samples created by his technique allowed Maurice Wilkins of King's College London to generate the X-ray crystallography images from which DNA's double-helix structure was revealed.
The discovery earned Mr Wilkins, James Watson and Francis Crick the 1962 Nobel Prize in Physiology or Medicine.
Australian Associated Press