MELBOURNE.- British art experts believe that one of Australia's prized paintings by Vincent Van Gogh could be a fake. The Melbourne-based National Gallery acquired it in 1940 for 20 million. The Sunday Times newspaper in London yesterday published claims by Van Gogh specialists that the work had been incorrectly attributed to the painter, and might be a forgery.

Skeptics have pointed out it is the only horizontal portrait by van Gogh, is not mentioned in any letters by the Dutch master, is mounted in a manner unusual for van Gogh and appears to have had the lower part, where a signature could have been, removed.

National Gallery of Victoria (NGV) director Gerard Vaughan conceded Monday that Head of a Man would be worthless if the bulk of art historians concurred with the view of Michael Daley, director of Art Watch UK, that the NGV's prize exhibit had 'all the hallmarks of a pre-existing picture tricked up to resemble a Van Gogh.'

"Any painting, unless you can trace its provenance right back to the studio of the artist and you can document every sale out of the studio of the artist - and there are many paintings in our collection when we can do that, in fact, so provenance research is obviously very important - but you eventually, at the end of the day, you have to trust your sense of connoisseurship, I suppose, your ability to judge quality in a painting."