The Vatican's top art historian shot down a report in its own newspaper that suggested a recently discovered painting was a Caravaggio.

The head of the Vatican Museums, Antonio Paolucci, wrote in the Vatican newspaper L'Osservatore Romano that the work was most likely a copy of an original by a Caravaggio-influence artist.

It was L'Osservatore itself that set the art world aflutter last week with a front-page article headlined A New Caravaggio, detailing the artistry behind the Martyrdom of St Lawrence, which was discovered in the sacristy of a Jesuit church in Rome.

The author of the article, art historian Lydia Salviucci Insolera, made it clear that she was not making any conclusions about the authenticity of the work and that more diagnostic tests were required.

But the impression given by the newspaper was that the painting was indeed a never-before-seen Caravaggio. The definitive-sounding headline appeared above the fold alongside a colour photograph of the dramatic painting - on the 400th anniversary to the day of the master's death.

The Vatican has in the past announced such art-world news in L'Osservatore, such as when it revealed last year that the earliest known icon of St Paul was discovered in a Roman catacomb just in time for the saint's feast day.