Art superintendent Rossella Vodret points out specific details in the painting The Martyrdom of St. Lawrence, which was believed to be a lost work by baroque master Caravaggio, in Rome on Tuesday. (Pier Paolo Cito/Associated Press)

A painting recently touted by the Vatican's newspaper as a possible new work by Caravaggio was unveiled in Rome Tuesday, but experts quickly rejected the canvas as a creation of the baroque master.

On Tuesday, the 183 x 130.5 centimetre canvas The Martyrdom of St. Lawrence — which depicts the saint being grilled to death and three executioners in the background — was unveiled to art experts at a Jesuit church in Rome.

Beginning in September, it will undergo X-ray and other testing, as well as extensive archival research, to determine its provenance.

However, even with the naked eye, the art officials and scholars who attended the unveiling agreed that the painting was likely the work of one or more of Caravaggio's followers, rather than by the master.

"It's a very interesting painting but I believe we can rule out — at least for now — that it's a Caravaggio," art superintendent Rossella Vodret said in an interview.

"The quality of the painting doesn't hold up."

According to Vodret and other experts present, the painting is uneven in artistic quality, which suggests that it was created by more than one person.

"The leg looks like a frog's leg. Caravaggio would never have made such a mistake," said art historian Marco Bona Castellotti.

Front-page claims

Last week, a front-page story in the Vatican's L'Osservatore Romano headlined "A New Caravaggio" suggested that the painting, which belongs to the Jesuits in Rome, could actually be by the Italian master.

The article was published on the 400th anniversary of Caravaggio's death, amid a host of celebrations and sparking a great fervour.

On Monday, however, a L'Osservatore Romano article penned by the Vatican's top art historian disputed the paper's previous front-page claims.

Under the headline "A New Caravaggio? Not really," Antonio Paolucci argued that the painting was not of the quality of the master artist and that it was a "modest" work at best.

With files from the Associated Press