A portrait stashed in a bank crypt in Athens could be the last painting Vincent van Gogh produced, according to some art experts and collectors who are attempting to determine the legitimacy of the picture found among the assets of a Greek world war two resistance fighter.

The discovery of the work, along with a notebook of sketches also supposedly drawn by Van Gogh, has raised the vision of the post-impressionist artiste having painted a third portrait of his physician, Dr Gachet, perhaps only days before a spell of psychosis induced him to entrust suicide at the age of 37. For art historians it would add to the debate that has surrounded the famous painting by one of the fathers of modern art.

"A lot of interest has been expressed in the work from very big museums and auction houses," its owner, Doretta Peppa, said. "A well-known institution will soon make an announcement about its historical background that will leave no doubt it is an original work by Van Gogh."

Peppa said the portrait's colourful history began in France when the Nazis stole it from a Jewish family during the second world war. After Hitler's forces marched into Greece in April 1941 it was brought to Athens, an exhibition centre for looted treasures.

The Athenian writer claims it was "liberated" by her father, Meletis, a prominent figure in the partisan movement, during a raid on a German train in the waning days of the occupation in 1944.