A brother and uncle of an American woman jailed for the murder of her Irish husband and father of two are to appear in a documentary to be screened on Saturday by a major US TV network.

Molly Martens Corbett, 35, and her father Tom, 68, a retired FBI agent, were convicted of the second-degree murder of 39-year-old Limerick man Jason Corbett at his US home at Panther Creek, North Carolina on August 2, 2015.

He had been bludgeoned to death by an aluminium baseball bat and paving stone while he slept.

Ms Martens uncle Mike Earnest and brother Connor appear in the CBS hour-long documentary as does Tracey Corbett Lynch, a sister of Jason’s and legal guardian of his children Jack and Sarah who now live in Limerick.

A three-minute long preview of the documentary has been released.

A statement on the Facebook page Jason's Journey said: “None of the participants have seen any of the documentary. After seeing the preview my gut reaction was, ‘Thank God, someone for Jason participated’, or else it would just have been another hour of sanctimonious lies and dribble from Mike Earnest and family.’

“We already witnessed their obscene fabrications on 20/20 (another US documentary on the ABC TV network) but this time the truth will be told and heard. To this day people still contact this page condemning Jason, solely based on that 20/20 program.

“Thank you to the friends and family members of Jason who not only refuse to allow his name to be tarnished, but stand up and take action.”

Both families detail the lives of the Martens and Corbett families and the events of the night Mr Corbett died. Mrs Corbett Lynch describes her younger brother as being, “an amazing human being, fun vivacious and a little bit giddy.”

Speaking ahead of the documentary, Mr Earnest said both he and a brother of his niece willingly took part in the programme: “I took part as did one of Molly's brothers. Additionally, one acquaintance of Molly (disguised) also took part. Disguised because of the threats and abuse received (due to what occurred).

Mr Earnest described his niece as being “kind-hearted” while her brother added that his sister, “loved others more than she ever loved herself.”

The American woman first met Mr Corbett when she moved to Limerick, as his children’s nanny following his first wife’s death Mags Fitzpatrick. She subsequently married Mr Corbett in 2011 in the US following the businessman’s relocation there.

The Martens pair pleaded not guilty to the charges and claimed self-defence was the reason behind their deadly actions. They have since appealed their convictions are currently awaiting the outcome of the North Carolina Court of Appeals ruling which is not expected for a number of months.

If the father and daughter fail to win a retrial with the Court of Appeal, their only option is the North Carolina Supreme Court.

Several more documentaries, both Irish and American are also in the pipeline on the events of surrounding the late father’s death.