The heirs of the Jewish art dealer Oscar Stettiner continue to go to law over Modigliani's 1918 "Seated Man with a Cane", which they consider their rightful property, believing it to have been seized from the estate of their forebear during…

A couple of weeks ago the court ordered the present owner of the disputed painting, the art dealer David Nahmad, to return it to Stettiner's heirs. Now it has further ruled that the heirs are entitled to interest for the period preceding the judgment in the case of the Modigliani looted by the Nazis. This may amount to several million dollars.

Do you know what the trouble is? Firstly, a great many court decisions may now be reopened in the light of this ruling, and the former good-faith owners of works of art once seized by the Nazis may be obliged to pay multimillion-dollar compensation simply for having held the property, and the longer the possession lasted, the larger the sums that may accrue.

Secondly, and this is usually ignored by the press, in this particular case the court disregarded the evidence that this very painting, "Seated Man with a Cane", was not in fact the painting that belonged to Stettiner at all.

The amount of compensation has yet to be determined. The heirs value the painting at roughly 20 million dollars at the time the suit was filed in 2014, while Nahmad's side puts it at 6.5 million. A hearing to establish the value, on which the final sum of interest will depend, has been set for September.

The judge remarked that he does not consider the outcome a just one, since there is no evidence that Nahmad knew of the painting's provenance when he bought it at auction in 1996. According to him, had the law allowed, he would have reduced the interest or waived it altogether, but New York State law and binding precedent do not permit it. Nahmad's lawyer, Luke Nikas, stated that the decision gives serious grounds for appeal, since the court established liability without a hearing on the merits, despite documents and testimony which, in the defence's view, prove that this particular "Seated Man with a Cane" never belonged to Stettiner