...experts have examined her, and the consensus is that she is from the school of Leonardo da Vinci, possibly even by da Vinci himself. Either way, it's a masterpiece, and could be worth millions. I've no idea if the man who gave the painting to my father knew any of this, or how it came to be in his possession.

Through my own research, I've become convinced the painting is Leonardo's final commission, at the request of Francis I of France and completed shortly before his death. I am equally certain that it depicts Mary Magdalene rather than the Virgin Mary, and that the infant in her arms is the child of Jesus – it would have been considered heretical by the church, and put the artist at great risk. But we won't know for sure until next year.

The Madonna is now locked up in a vault, awaiting expert appraisal. I miss her terribly, but I hope she will be the catalyst for a great good. When the painting finally goes to auction, I've pledged to use the money raised to set up a foundation named after Leonardo's 16-year-old peasant mother, Caterina, who had her child taken from her, to provide support for children in care. I'd like to believe such an act would be very much in the spirit of the great man himself. I won't sell to a private collector: it's vital that she ends up in a gallery or museum, where anyone who wants to see her will be able to – myself included.