Sarah and Peter Hillary will bring the action against the executors of their father's estate in the High Court at Auckland next month.
But the dispute is actually with the Auckland War Memorial Museum over the interpretation of a clause in Sir Edmund's will.
It gives "my personal papers, diaries, maps, colour slides, photographs and other written and illustrative material relating to my life and adventures" to the museum, "with the proviso that [Sarah and Peter] shall have ready access to and the right to publish such material if they think fit".
The clause says no other person or corporate body may publish the material without the consent of the Hillary children for 20 years after Sir Edmund's death.
The museum opposes the Hillarys' view they have ownership rights to Sir Edmund's possessions.
Its interpretation is that the clause does not bind it in any way, lawyer Richard Wilson, one of the will's executors, says.
Mr Wilson and co-executor John Jackson, a lawyer, are named as defendants in the action brought by the Hillarys.
"There is a provision . . . which says no-one can publish material for 20 years without the consent of Peter and Sarah," Mr Wilson said.
"The museum is alleging that doesn't bind them, that they can publish without the consent."
Peter Hillary said the dispute began last June, adding to an already distressing time after their father's death in January.
"The museum is asserting absolute ownership - complete intellectual rights over how it's used.
"This is our history - a lot of it is family stuff, photos of the children, our mother, our family.
"I don't think it's unreasonable that we are consulted about it."
After an experience with the Canterbury Museum involving items the museum believed it owned but which Sir Edmund had as a loan, Mr Hillary said his father had met then Auckland Museum director Dr Rodney Wilson at least twice to discuss the issue.
He was concerned Auckland Museum would not recognise that Sir Edmund's children had the ultimate say in how his possessions were used.
"I think he'd be horrified that this is happening. He was concerned and that's why he had those meetings."
The recent experience with museum staff had led to a rethinking of future contributions of his father's personal possessions to the museum.
Mr Hillary said Auckland Museum director Vanda Vitali had been "very difficult to deal with".
He had repeatedly asked "basically for a cup of coffee to talk things over. She just won't have it."
An Auckland Museum spokesman said yesterday Dr Vitali would not comment on the issue.
But the museum said it supported having the interpretation of the will examined in court.
"This clause, which lays out Sir Ed's wishes about his historical papers, is interpreted by the museum in a way that guarantees access in perpetuity for researchers, scholars and the people of Auckland," a formal statement said.
"This we see as our defining responsibility, in order to honour the desire of Sir Ed for his papers to be housed here. Peter and Sarah Hillary have a different interpretation."
Mr Hillary said the family had always supported keeping their father's possessions in the museum to share with New Zealanders, but it was important for the museum to show respect and acknowledge that the items were also family heirlooms.
"It's a bit like me saying to you, `I have all your family's photographs of your family holidays, outings with your parents and family history and I'm going to do whatever I want with it.' We just want to be consulted."
- The New Zealand Herald
