The team try to find out whether a beautiful English landscape is a work of national importance - a lost masterpiece by John Constable and quite possibly an alternative view of his greatest work, The Hay Wain. Now owned by a British businessman, the painting appears to have all the hallmarks of Constable's sketches - his more impressionistic, preparatory works. If genuine, it could be worth at least £2 million.

There are few more iconic paintings in British art than Constable's The Hay Wain. A picture with a direct link to this milestone in British art would be the holy grail for any collector or museum and the picture appears to depict the very same scene, Willy Lott's cottage on the banks of the River Stour.

The trouble is, Constable is one of the most faked artists of the 19th century, and the painting has a chequered past. Thirty years ago, several top Constable experts decided that it was not an authentic work. It is a particularly personal case for Philip Mould, who briefly owned the painting in the past but had to let it slip through his fingers after he failed in his attempts to prove its authenticity.

Now scientific analysis techniques have moved on and neglected records can be searched more deeply online, can the latest advances and deep research into the picture's provenance turn up enough evidence to prove that it is a genuine work by John Constable? Show less