The American woman charged with the murder of her Irish husband is said to have admitted killing him, a US court was told.
Molly Martens Corbett (32) is alleged to have made the admission to her sister-in-law in the hours after her husband, Jason Corbett (39), died from head injures at their home in North Carolina.
Details of the alleged admission were outlined by the deceased's sister Tracey Lynch at a court hearing last August.
In a separate legal submission, Mrs Lynch also claimed Ms Martens had told a family friend she "wanted to leave Jason because she did not love him anymore and did not care what happened to him".
However, Ms Martens is alleged to have decided against this because she would have no right to his children.
Mrs Lynch's allegations were aired at a behind closed doors hearing to decide on the guardianship of Mr Corbett's two children.
Details of the alleged admission can now be disclosed after a transcript was made public by the Davidson County Superior Court.
At the hearing, Mrs Lynch and her husband David successfully applied for guardianship of the children, Jack (11) and Sarah (9), in line with Mr Corbett's wishes in his will.
Mrs Lynch argued under questioning that the children needed protection from their stepmother, Ms Martens, who, she said, had admitted to killing her brother.
"I spoke to Molly after the event and her mother. And Molly indicated that she killed my brother," Mrs Lynch testified.
Ms Martens and her father, former FBI agent Thomas Martens (65), were both charged with second degree murder and voluntary manslaughter earlier this week. Mr Martens told a 911 dispatcher he struck his son-in-law with a baseball bat during a row.
A spokesman for the two accused, Ms Martens' uncle Mike Earnest, has said both will plead not guilty and will say that they acted in self defence.
Other allegations were made by Mrs Lynch at the guardianship hearing. These included claims that Ms Martens was violent towards Jack Corbett on a number of occasions.
It was also claimed Ms Martens would drink alcoholic margaritas from a cup throughout the day, including when she was driving the children.
Mrs Lynch said she had told Ms Martens she was "crazy" and shouldn't be doing it.
She alleged Ms Martens was prone to bouts of erratic behaviour and had said she suffered from bipolar disorder.
Mrs Lynch also told the court Ms Martens' relationship with the children was "unhealthy for very different reasons".
"Molly was very possessive of Sarah and didn't really demonstrate a caring for Jack," she testified.
Ms Martens has denied claims made about her behaviour and indicated she would appeal the guardianship order.
Police found Limerick-born Mr Corbett dead at his home in Wallburg, North Carolina, in the early hours of August 2 last.
The guardianship hearing took place a fortnight later. Both of his children were born to Mr Corbett's first wife Mags, who died in 2006.
He later formed a relationship with Tennessee-born Ms Martens after she came to work for him as an au pair. The couple married in 2011 and moved from Ireland to North Carolina.
Mrs Lynch testified that her brother had decided not to allow Ms Martens to adopt the children. She also said he had been homesick and wanted to return to Ireland permanently.
The murder trial is likely to get underway in around one year's time. The maximum sentence for a charge of second-degree murder - defined as intentional killing with malice but without premeditation and deliberation - is 40 years.
Manslaughter carries a maximum sentence of 17 years in North Carolina. The jury in the trial can chose to convict on either charge or acquit the pair.