The NHMF said it would give the money to The National Galleries of Scotland and the National Gallery in London, which are attempting to raise $75 million to purchase jointly the painting from a private owner who wants to sell it at the end of the year, the BBC reported.

The 16th century masterpiece has been on display alternately at the two national galleries for more than 200 years.

"We have moved quickly to show our support and hope this persuades others to dig deep to make this dream a reality," Jenny Abramsky, chair of the NHMF, told the BBC.

"This extremely generous and wholehearted support represents a major boost for the campaign to acquire this superlative masterpiece for the national collections," said John Leighton, director-general of the National Galleries of Scotland.