A painting on loan to the Museum of St Albans has been identified as a Thomas Gainsborough following an investigation by the BBC’s Fake or Fortune.

Broadcast on Sunday, February 9 the television programme attributed the portrait of former St Albans Mayor, Joseph Gape, to the renowned, eighteenth-century English portrait and landscape painter.

Mr Gape, was Mayor of St Albans three times in 1746, 1761 and 1797 and also served on the city council for more than 50 years. It is possible that this portrait may relate to his second mayoralty.

Unattributed until now, the painting was passed down through the Gape family until the 1960s. It was then loaned to the council for display in the mayor’s parlour at the Civic Centre. More recently, the painting was moved to the museum.

The painting was spotted by the producers of Fake or Fortune on the Public Catalogue Foundation’s website, which gives the public access to oil paintings held in public ownership or on long-term loan to public institutions.

A leading expert in Gainsborough paintings, Hugh Belsey, examined the painting and was able to identify it as a Thomas Gainsborough.

Councillor Mike Wakely, Portfolio Holder for Sports, Leisure and Heritage at the council, said: "It is fantastic news that the Museum of St Albans can now attribute this portrait to Thomas Gainsborough, one of the leading painters of the eighteenth century. The fact that Joseph Gape was painted by Gainsborough suggests that he was a man of significant wealth and influence.

"The painting is now on display in the entrance foyer to the Museum of St Albans until the summer. Make sure you come along to see the portrait by this famous artist."

The Gape family is one of St Albans’ oldest families. Gapes are referred to in local records as early as 1485. They played a leading role in city affairs, taking part in municipal and parliamentary politics. At least 16 members of the Gape family have held the post of Mayor of St Albans at various intervals up to 1829.

The Gapes were considerable land owners with land in Fishpool Street, Sopwell Lane, Romeland and Holywell Hill. The original prosperity of the family was based on tanning, a trade that played a key role in St Albans’ economy from the medieval times onwards.

Tanning is a process of treating skins of animals to produce leather and there were at least four tanneries in the City in 1360. St Michael’s Manor Hotel was the site of the original Gape tannery, the land having been obtained by Henry Gape after the dissolution of the monasteries.

John Gape built St Michael’s Manor in 1585, which was passed down through the family until it was acquired by the Newling Ward family in 1965 and is now run as a hotel.