Robert F. Kennedy Jr's accusations about his estranged wife's behaviour before her suicide amounted to "a brutal psychological weapon", her family said.
Mary Richardson Kennedy's relatives issued a statement saying an affidavit in the Kennedys' divorce case, disclosed on Sunday, was "scurrilous" and "full of vindictive lies".
In the affidavit, dated September 2011, Robert Kennedy accused Mary Kennedy of abusing his children from an earlier marriage and stealing from them and him.
It asked a judge for an order of protection to keep her from physically attacking him, showing up uninvited at his homes and denigrating him to their children.
Mr Kennedy, son of Senator Robert F. Kennedy and nephew of President John F. Kennedy, also asked that his wife be required to remain sober in front of their children and not threaten suicide in their presence.
Mary Kennedy hanged herself last month at the family's estate in Bedford. The divorce was pending.
One of Mary Kennedy's brothers tried to get custody of her body before she was buried near the Kennedy compound in Massachusetts.
The Richardson family's statement said the affidavit, posted online by The Daily Beast as part of a Newsweek magazine article, "was written by Bobby Kennedy as part of a contentious custody battle and was nothing more than a brutal psychological weapon in the divorce case".
It said the release of the document was proof of the "emotional and psychological abuse that Mary endured during the last years of her life, and also in death".
"We hoped Mary could rest in peace," it said.
Messages left at Mr Kennedy's office at a legal environmental clinic and his divorce lawyer's Manhattan office were not immediately returned.Reuse content