The Duke of Buccleuch, one of Britain's richest men whose Leonardo da Vinci painting was stolen from his castle last week, yesterday urged the Government to help owners of historic homes to provide security for their collections.

He said the theft from Drumlanrig Castle, in Dumfries and Galloway highlighted the difficulty of providing tight security while allowing public access to great works of art. The masterpiece, Madonna with the Yarnwinder, valued at £40m, was stolen on Wednesday by two men posing as visitors. Police have released an e-fit and CCTV footage of the suspects, including an e-fit of a man who bought the Volkswagen Golf getaway car.

The Duke said many owners of historic homes were committed to opening them to the public but needed more help.

"For many, the cost of providing access to these properties is very high, with them facing security and employment costs," he said.

"Seldom does the revenue generated by visitors cover these costs. It is also essential that politicians recognise the role historic houses fulfil."

The painting is considered the most important work stolen in the UK for decades.