The daughter of a minister involved in the Queensland government’s handling of a controversial mining project works for the company.

Ian Walker took a donation from a director of New Hope Group for his 2012 election campaign, and subsequently oversaw its application to expand the mine as acting minister for state development.

New Hope Group hired Walker’s daughter, Alice Walker, as a communications officer last year.

The premier, Campbell Newman, has denied suggestions that donations by New Hope and its owners helped influence government approval of its Acland mine expansion just before Christmas.

Walker was science minister when his department approved dust emission levels from uncovered trains carrying coal from mines, including Acland, in August 2013.

He acted as state development minister, inviting public comment on Acland’s revised environmental impact statement, for two weeks in January last year.

Walker received a $2,000 personal cheque from New Hope director Bill Williams in 2011 for his campaign fund to run in the state seat of Mansfield.

Alice Walker, who previously worked as a media adviser to federal Liberal MP Jane Prentice and Nationals MP Bruce Scott, began work at New Hope on 28 April.

Ian Walker told Guardian Australia in a statement that he notified the office of deputy premier Jeff Seeney when his daughter took the job with New Hope.

“I am scrupulous with any conflict of interest obligations, and comply to the highest standard,” he said.

“Children of politicians have the right to work in the private sector for companies that may deal with the government.

“It’s no secret Alice works at New Hope, which is on her LinkedIn profile.”

New Hope and its parent company, Washington H Soul Pattinson, declared donations of $700,000 to the federal Liberal party and $1,900 to the LNP between 2011 and 2013.

The Queensland government’s approval of Acland has come under attack in recent days from radio host Alan Jones, who was born in the town and accuses Newman of lying to him by promising to block the expansion before the last election.

Newman, who said he did not want to engage with Jones’s claims, then repeatedly blamed the controversy on his Labor opponents, replied “of course not” when asked if donations played any role.

In a 2013 press release, Walker said the government “in keeping with our 2012 election commitment … did not support New Acland Coal’s original 2007 expansion plan due to its effect on high quality agricultural land and proximity to local townships”.

Seeney announced approval for the mine on 19 December, after the government cut the annual limit on coal production from 10m tonnes to 7.5m tonnes, and the life of the mine by 13 years.