Mossman took flights for troubled son

A former NT ministerial adviser has told his corruption trial he accepted discounted flights for his son because he was worried the boy would self harm while he was away.

Paul Mossman has pleaded not guilty in the NT Supreme Court to five counts of corruptly receiving a benefit, relating to allegedly discounted and free travel when he was chief of staff to former Country Liberals minister Bess Price.

The prosecution argues he accepted the flights from Latitude Travel, owned by Xana Kamitsis, in return for giving the company more than $300,000 in exclusive government travel contracts.

Mossman allegedly accepted return flights to New York for him and his son Nathanial on a trip with Ms Price in 2014, with the accused paying a $1000 deposit and the rest picked up by Latitude Travel.

The 44-year-old said he took the flights because he was a single parent and didn't want to leave his son, a "difficult child" who had ADHD, behind for 10 days.

"I was really worried he would self-harm ... he was prone to violent behaviour," Mossman told the court.

The former high-ranking government staffer has been friends with Ms Kamitsis since 2005, and he stressed she didn't offer the "loan" to curry favour.

"I believe I received it because she knew about Nathanial, and the horrible situation I was in," he said.

He said Ms Price knew the travel agent deposited $1500 into their accounts as another loan after their New York hotel mistakenly withdrew cash from their cards, despite her denying any knowledge of the incident.

The senior public servant said he also took free flights to Kuala Lumpur and accommodation the year before as a personal favour to the travel agent to help her "fill seats" and impress an airline.

"She stressed to me a number of times it had nothing to do with work. It was friend to a friend," he said.

The company again paid $1100 for return flights for Mossman and his daughter Laura from Darwin to Sydney in 2014, the Crown says.

Mossman, who was an advisor to ex chief minister Adam Giles, insisted he gave Ms Kamitsis his credit card details for payment, and was later shocked to discover she had never charged him.

Mossman was repeatedly accused of lying under cross examination from prosecutor David Morters on Wednesday until his daughter left the courtroom in tears.

Mr Morters asked about Mossman's involvement in an investigation into allegations of misconduct by Ms Kamitsis, who was operating unlicensed when they first became friends.

Mossman, who has worked in the public service for 27 years, was a consumer affairs compliance officer at the time.

"You had a bias and... you have no regard for the rules," Mr Morters said.

"I reject that outright," Mossman said.

"It's only a conflict of interest if it influenced me, and it didn't."

The trial before Justice Peter Barr continues.