The man, who cannot be named for legal reasons, has pleaded not guilty to four counts of aggravated sexual intercourse with a child under his care, three while she was between 10 and 14 and a fourth offence while she was between 14 and 16.

He is also charged with committing an aggravated act of indecency with a person in his care.

After splitting with the girl's mother when she was just five and winning custody of his child, the man and his daughter moved to a farm in the region in 2002 where they lived with his new partner.

It is alleged that some time between August 2005 and September 2006, when the girl was 12 or 13, her father had sex with her for the first time, telling her it "wasn't going to hurt" and that they would "try again another time" after the act.

In the weeks following, the man allegedly had sex with her again and on another occasion forced her to perform oral sex on him.

He is alleged to have had sex a fourth time with her, when she was 14, at a reserve near Narrandera.

The man's alleged actions went undiscovered until a family barbecue at the farm in September 2011, where his daughter allegedly told the man's partner that he had sex with her after being asked if he was having an affair.

He was then confronted by his partner, the court heard.

According to the prosecution, he is alleged to have responded by saying "I only done it a couple of times".

In the days following the barbecue, he allegedly texted his daughter, telling her he was "sorry" and not to blame herself.

The man then spoke to police voluntarily and told them it was impossible for the allegations that he had sex with his own daughter to be true and her stepmother had fabricated the story as revenge for the affair she believed he was having.

"This is the work of a woman scorned," he allegedly told police.

The trial continues.