The High Court case could make millions for Mary Danowski, nee Moore, and her three children if they win title to the disputed works. The four, the indirect beneficiaries of the sculptor, would have inherited all his estate if the charitable foundation had not been set up.
The case could also set an important precedent for the art world because it will clarify conventions about the extent of an artist's rights to 'artist's copy' - the sculptures cast by the artist at the end of an edition for personal use.
Mrs Danowski, Moore's only child, was the driving force behind the 1976 creation of the charitable foundation to protect her father's legacy.
It was set up after Moore had considered emigrating to Switzerland for fear the Inland Revenue might create problems for him - by the mid- Seventies he was making more than pounds 1m profit a year, the court was told. Mrs Danowski encouraged Moore to set up the foundation as a way of protecting his art after his death: he was very worried his sculptures might meet the same fate as Rodin's, with extra editions of his sculptures being cast after he died to raise money, Lord Irvine QC, for Mrs Danowski, said.
Mr Moore gave the charity his entire estate with the exception of Hoglands, his Hertfordshire home, and his studios. But the court was told that since Moore's death in 1986 a dispute had arisen over who owned works Moore created between the foundation being set up and his death.
In some cases the disputed works were 'artist's copies'. In other cases the works are sketches of planned sculptures, or preparatory artworks in plaster.
The artist's copies formed 95 per cent of the value of the disputed works, the High Court heard. They were not the property of the Henry Moore Foundation but his beneficiaries, because the artist had created them privately.
The case continues today.