Mr Hassell said he eventually opted to make an official internal complaint which led to a an investigation.
Another CBH director at the time has supported claims the board received a report on Mr Newman’s behaviour.
Mr Hassell, who has twice stood as the National Party candidate for O’Connor, denied he was making his allegations public to further his political ambitions or influence the CBH board elections.
Mr Newman was contacted for comment but did not respond.
A CBH spokesman said its directors and employees were expected to “adhere to the highest standards in their professional behaviour and are held accountable at all times”.
“All complaints in relation to alleged inappropriate conduct are treated seriously and fully investigated,” he said.
“CBH respects the right to privacy of anyone lodging a complaint and does not comment on individual cases.”
CBH, one of Australia’s most powerful farming organisations and a part owner of a network of flour mills in South-East Asia, reported revenue of $4.19 billion in 2019 but suffered a net after tax loss of $29.7 million on the back of poor performance in it trading arm.
Prominent business leader Diane Smith Gander became CBH’s first ever female director in 2011 before quitting in 2014. Her replacement as an independent director, Samantha Tough, lasted just nine months before she resigned.
In 2018, Kondinin farmer Natalie Browning made history in becoming the first woman elected as a grower director of the 87-year-old co-operative.