The portrait was previously attributed to lesser-known female artist Maria Cosway (1760-1838) but following research the programme was able to demonstrate it was in fact by Lawrence and therefore valued at around £500,000, rather than the £8000 if it had been by Cosway.
The portrait is owned by Hugh and Mirabel Cecil and the sitter is Hugh’s distant ancestor Peniston Lamb. It has been passed down through generations of the Cecil family as the work of the Cosway.
But when art dealer Philip Mould first saw the picture around two years ago he believed it to be the hand of one of his favourite artists, Lawrence.
Mould said: “It had all the signs of a painting by the great Thomas Lawrence but clinching evidence came later. Using science to look beneath his wig at Lawrence’s frenetic brushstroke was a revelation. It really is such a thrilling find by the team, and our most glamorous discovery in over 30 episodes of Fake or Fortune?”
The programme revealed how the team investigated the portrait’s history by visiting some of the grandest houses in the UK.
Lamb was part of the well-connected, high-society Melbourne family and the portrait passed through a number of branches and relations in various locations over the years.
Lawrence experts, art historian Prof Brian Allen and Dr Peter Funnell, a former curator at the National Portrait Gallery, studied the research that the Fake or Fortune? team had compiled.
Funnell said he believed it to be “a very fine example of Lawrence’s early works”. Allen endorsed this view and said he believes the picture dates from c.1790. He speculated that it was painted at the same time as the famous portrait of Queen Charlotte in the National Gallery.
Following the revelation on the TV show, Mirabel Cecil conceded that the family would move it from the corner of their room and give it pride of place. She said despite the increase in value, she hopes it will not be sold and will stay in the family.
Fake or Fortune? was on BBC One at 9pm tonight (August 1). The next episode of the eighth series is due to be broadcast on August 8.