Home Affairs Minister Peter Dutton says he reviews every visa case on its merits following revelations he personally intervened to stop the deportation of a third au pair.
Mr Dutton, who's facing an upcoming Senate inquiry over his involvement in the cases of two other au pairs, sought a briefing on the third after she arrived in Australia in November 2015.
Border force officers detained the woman for questioning over concerns she intended to work in the country.
Mr Dutton reportedly used his powers to approve the 27-year-old's release after his office was lobbied by AFL boss Gil McLachlan on behalf of a relative in South Australia.
Documents obtained by the ABC show Mr Dutton granted the woman a three-month tourist visa, on the condition she did not work.
"Having regard to this person's particular circumstances and personal characteristics, I have decided to use my discretionary powers ... as it would be in the public interest to grant this person a visa," he wrote.
"In the circumstances, I have decided that as a discretionary and humanitarian act to an individual with ongoing needs, it is in the interests of Australia as a humane and generous society to grant this person a visitor visa (subclass 600) for a period of three months."
Mr Dutton released a strongly-worded statement refuting any suggestions of impropriety.
He said immigration ministers receive hundreds of inquiries each year on individual migration matters from members of the public, organisations, journalists and MPs.
"There are long standing intervention powers provided to ministers to consider and deal with these representations," Mr Dutton said in a statement on Tuesday.
"I consider cases on their merits. Any suggestions cases are determined on any other basis, including whether I knew the individual who referred the matter, is completely ridiculous.
"There is an administrative process to be followed and it has been followed in every instance."
Greens Senator Nick McKim and opposition immigration spokesman Shayne Neumann said Mr Dutton has some serious questions to answer.
"Labor expects the new prime minister Scott Morrison to ensure his minister fully cooperates with the Senate inquiry and its efforts to get to the bottom of these matters," Mr Neumann said.
The AFL has been contacted for comment.
Last week, Labor successfully moved to establish an inquiry into "allegations concerning the inappropriate exercise of ministerial powers with respect to the visa status of au pairs".
The upper house committee will investigate two separate decisions by Mr Dutton to overrule his department's denial of entry to two young women in 2015.
