A lost Victorian portrait, which has been rediscovered on the BBC's Antiques Roadshow, has "stunned the art world".
The work is by Neoclassical painter Sir Lawrence Alma-Tadema, who is "the most valuable Victorian artist today" after one of his large paintings sold for $36 million, according to the programme's pictures expert Rupert Maas.
The treasure features the engraver Leopold Lowenstam, whose great-great grandson brought it to an Antiques Roadshow event at Arley Hall, near Northwich, Cheshire, in June. It was a wedding gift to Mr Lowenstam, a close family friend, and his wife Alice Search in 1883. She was the governess of Sir Lawrence's children.
The portrait was exhibited at the Royal Academy a year later.
Mr Maas said: "Tadema holds the record for a Victorian painting at $36 million for an enormous picture sold in New York a few years ago. This one doesn't quite reach that because it's not of a Neoclassical subject and it's not huge. But it is very, very good, and shows another, more painterly side of his work than the girls in togas sitting on marble benches that he is known for.
"I think this might be one of the best pictures we've ever seen on the Roadshow in its entire history. There are hardly any portraits of engravers at work at all, and this is one of the most telling and beautiful."
The Dutch painter's work inspired US filmmaker Cecil B DeMille.
Mr Maas added: "The news of the discovery of this lost important work has stunned the art world and I'm delighted people will get the chance to see it restored and alongside other great works."
The now-restored portrait is part of the international touring exhibition of Sir Lawrence Alma-Tadema's work, organised by the Dutch Museum of Friesland. It starts in Leeuwarden in the Netherlands on October 1 and is due to arrive at Leighton House in London in autumn 2017.
Curator Marlies Stoter said: "The careers of both men have many similarities, they left the Netherlands at an early age and moved to London in the beginning of the 1870s. Soon after they became acquainted they started working together.
"The reproduction prints Lowenstam made after Alma-Tadema's masterpieces helped to make the painter famous. We are delighted to hang their portraits next to each other in our exhibition."
Programme makers are tight-lipped on the value of the painting, which is set to be announced during the next Antoques Roadshow broadcast on BBC One on Sunday at 8pm.