The first part of the two-part miniseries, starring Mandy McElhinney as Gina Rinehart and Sam Neill as Lang Hancock, aired last night.
The telemovie focuses on Hancock’s marriage to Rose Porteous and the rift it caused between him and his daughter.
But long-time Hancock executive Watroba said the series was filled with glaring inaccuracies.
“Despite repeatedly bringing it to Nine CEO David Gyngell’s attention, many scenes broadcast last night were fictitious, unfounded or grossly distorted, and some simply never occurred,” he said.
“I worked for Lang Hancock and have been with Mrs Rinehart’s company Hancock Prospecting since 1991 so I have a good grasp on what actually took place.”
Watroba said despite the television portrayal, Rinehart had a loving relationship with both her parents, as well as her husband, the late Frank Rinehart.
He added that scenes where Hancock said terrible things about his daughter’s appearance, including calling her a “slothful, vindictive, devious baby elephant”, were fabricated.
Lang Hancock died in 1992.
Watroba also denied that Rinehart participated in, or condoned doing deals with Romania’s Nicolae Ceausescu.
“I know the facts, and this show has turned out to be a tacky grab for ratings, damaging the memory of good Australians along the way,” he said.
“Since starting promotion of the show, Channel Nine has not bothered to fact-check anything despite repeated offers when people have pointed out mistakes.
“Sadly Channel Nine has seemingly gone out of its way to cause undue damage and upset to those currently living and the memory of those no longer with us.”
According to TV Tonight, the first part of House of Hancock was the second most-watched show of Sunday night with 1.3 million viewers.