Export rules need to be strengthened to prevent treasured artworks and objects being removed from the country by foreign buyers, according to the Director of UK charity Art Fund.

Stephen Deuchar said private buyers had exploited “avoidable loopholes” in the export control system to remove £278 million worth of art from the UK between 2011 and 2016. According to Arts Council England, export licences for 41 ‘national treasures’ were granted during this period. The exodus of artworks included:

• Picasso, ‘Child With A Dove’ (£50 million)

• Francesco Guardi, ‘Venice: A View of the Rialto Bridge from the Fondamenta del Carbon’ (£26.7 million)

• Rembrandt van Rijn, ‘Rembrandt Laughing’ (£16.5 million)

• Veronese, ‘The Triumph of Venice’ (£15.4 million)

• Marble statue of Aphrodite from Syon House (£9.6 million)

• Christian van Vianen, Dutch silver ewer and basin (£7.5 million)

In contrast, the export control system secured 32 treasures for the nation including a gold and turquoise ring once owned by Jane Austen.

Under the current system, the Department for Culture, Media and Sport can place a temporary export bar on important objects, which meet or exceed specific age or monetary value thresholds. The bar prevents overseas buyers from removing the works immediately to give UK institutions the opportunity to raise funds to match the purchase price. If fundraising is successful, convention dictates that the work should be sold to the institution.

Defying convention, buyers are understood to be refusing to sell to the UK institutions that successfully raise the matching sum. Most recently, a buyer in New York refused to sell ‘Portrait of a Young Man’ by Jacopo Pontormo to the National Gallery after it matched the £30 million price tag.

Deuchar stated that these “gentleman’s agreements” undermined the current export system and that “proper legal muscle” was required to stem the flow of artworks of national importance abroad.

Others have praised the system for striking the right balance between the needs of public and private collectors. Art historian and dealer Bendor Grosvenor said the current controls avoided excessive government interference with private assets.

“Something about art brings out the socialist in everyone. We sometimes think it must belong to the people”, Grosvenor said.