Pauline Hanson charged taxpayers almost $9,000 for a chartered plane to attend an event honouring the mining billionaire Gina Rinehart’s donation to a private agricultural college, parliamentary expenses data shows.

The One Nation leader flew from Tamworth to Avalon in October 2025 to attend the opening of new student accommodation at the private Marcus Oldham College in Geelong, with the chartered flight costing $8,870.

Details of the flight, released from the Independent Parliamentary Expenses Authority on Wednesday night, come as Hanson faces growing scrutiny of her use of taxpayer-funded entitlements that are intended to support the parliamentary business of a sitting member.

Guardian Australia revealed this week that Hanson had made multiple taxpayer-funded travel claims totalling $8,900 for trips which included headlining political fundraisers for One Nation across the country in the lead-up to the last election.

Under the rules governing use of taxpayer-funded travel, MPs and senators must ensure their claims meet the “dominant purpose test” of parliamentary business, and “must use public resources for parliamentary business in a way that achieves value for money”.

According to publicly available flight data, the private chartered plane left Tamworth at 8.33am on 19 October, the day of the event, and landed at Melbourne’s Avalon airport – a 25-minute drive from the college – shortly before midday.

A spokesperson for Hanson told Guardian Australia the cheapest option available was chosen as there were no commercial flights between Tamworth and Avalon.

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The One Nation leader had been in Tamworth for a party dinner on Saturday 18 October, the night before the Rinehart event, amid speculation of Barnaby Joyce’s defection to the rightwing minor party.

Hanson had been invited to the event by Rinehart, which was to celebrate the official opening of Nicholas Hancock House, an $11m student accommodation building for the agricultural business college named “in honour of both sides of Mrs Rinehart’s family”.

At the event, Hanson told the audience she was “honoured” to attend at Rinehart’s “kind invitation”.

Hanson’s spokesperson told Guardian Australia she attended the event as the college “provides many Queensland students a home away from home during their time studying at Australia’s only independent agribusiness and agricultural business management college”.

“She also had discussions about increases in HECS loans imposed on students attending the college, a private institution which receives no taxpayer funding,” the spokesperson said.

During a question and answer session at the event, the Victorian Liberal MLC Bev McArthur asked Hanson about a federal tax imposed on the Fee-Help scheme for students enrolled in private colleges.

Hanson said in response that “we are overtaxed in this country”.

“If it was One Nation, we’d get rid of payroll tax, a lot of these other taxes that we have. It is something that I do need to have a further look into. I was not aware of it, so I will. Thank you for bringing it to my attention.”

Rinehart had donated $2m to the college, where students pay more than $70,000 a year for tuition and on-campus accommodation. She was expected at the event, but did not attend.

However, Rinehart’s private jet flew from Perth to Melbourne on the same day, seemingly to collect Hanson. Guardian Australia previously revealed that the Queensland senator flew to Sydney from Melbourne’s Essendon airport on Rinehart’s Gulfstream G700 later that day, which Hanson had failed to declare within the timeline required under parliamentary rules.

Hanson’s office said the senator travelled to Essendon airport via hire car.

The expenses data shows the Queensland senator then flew back to Brisbane from Sydney on Monday 20 October, costing $1,090.64.

Asked at a press conference in Adelaide last month whether she had received any flights or transfers from Hancock Prospecting to or from the 19 October event, Hanson initially said: “No … if you are going to try to say that I am being funded by Gina Rinehart, the answer is no.”

Asked again if she received any flights or transfers to or from the event, Hanson replied: “I can’t remember.”

She updated the register on the same day, following Guardian Australia’s report. Last year, the senator similarly failed to properly declare that she and her chief of staff, James Ashby, had received flights from Rinehart’s company Hancock Prospecting to travel to and from Florida, where they also stayed at Rinehart’s $66m Palm Beach mansion.

Hanson’s use of taxpayer-funded travel has previously been the subject of an assurance review by the independent expenses watchdog, after she claimed almost $5,000 to attend Gina Rinehart’s 70th birthday party in Perth in 2024.

Her office provided diary entries that showed she met with senior executives from Rinehart’s company, Hancock Prospecting, which were used to justify the trip was related to her parliamentary duties. She was cleared of any wrongdoing.