Mike Pezzullo, a former Labor staffer turned senior bureaucrat who lobbied for hardline border policies, has won favor and hatred in equal terms.
At the time of publishing, Pezzullo has remained away from his role as the chief executive of the Department of Home Affairs.
Lynelle Briggs, the former leader of the liberal party, is investigating his conduct after numerous texts he allegedly exchanged with the Liberal Party powerbroker Scott Briggs.
His future hangs in the balance, engulfed in scandal, with few expecting the man once compared to a cockroach to survive.
A potential successor has already taken charge of his department, and as for what happens next, a diplomatic post is suddenly looking unlikely.
As a graduate in 1987, Michael Pezzullo joined the Department of Defence.
After a stint with the Department of the Prime Minister and Cabinet, he joined the staff of then Labor foreign minister Gareth Evans in 1993.
Pezzullo stayed on Labor when it went into opposition and spent four years as the deputy chief of staff to Labor opposition leader Kim Beazley.
For the last 21 years, he's risen in the public service, becoming the Secretary of the Department of Immigration and Border Protection in 2014, a role he assumed under a coalition government.
Pezzullo helped develop the Australian Border Force, a highly visible arm of the government's push to deter illegal arrivals.
In 2017, he became the head of a beefed up law enforcement department known as Home Affairs. As a central architect of that department, Pezzullo worked closely with Peter Dutton as the minister in charge of the portfolio.
A no-nonsense boss, he's an eager texter and has attracted headlines over the years for his approach to dress standards, for his declaration of war on jargon and embarrassing writing and for warning the 'drums of war' were beating in the Indo-Pacific in 2021.
A stickler for rules, he defied pressure from then prime minister Scott Morrison to break with convention and publicise the interception of a suspected asylum seeker boat.
When Labor won power last year, Pezzullo remained in charge of Home Affairs despite a push from some within the party to move him out of the position.
But his grip on power took a hit when9 reported a trove of alleged text messages that it received legally from a third party.
The published messages were with Liberal powerbroker Scott Briggs, and range from ridiculing senior Coalition ministers to advancing the advancement of right-wing Liberals and trying to convince the government to introduce laws to pressure media to prevent the publishing of national security stories.
Briggs has played a significant role in the political scene, including as deputy director of the New South Wales branch and president of the federal electoral conference in Morrison's seat of Cook.
Pezzullo hasn't made any comments about the matter, and the ABC has not independently verified the alleged text messages.
The investigation will focus on whether Pezzullo has breached the public service code of conduct, which requires bureaucrats to be independent and apolitical.
After the alleged messages emerged on Sunday evening, Home Affairs Minister Clare Oconducted himself in a thoroughly professional way in my dealings with him.
Former Liberal Attorney-General George Brandis, no ally of Pezzullo when he was in government, offered a scathing assessment.
The Greens have vowed that the government should sack Pezzullo.
The BBC has spoken with suspect the scandal will fast-track changes that have loomed over Home Affairs since Labor came to power.
The former senior figure at the Department of Prime Minister and Cabinet became the second in command of Home Affairs in October.
The government has asked Pezzullo to lead the department, but Pezzullo remains standing aside.
Government sources say Pezzullo was set to replace him as the president of the United States, until his term expires in October next year. They now expect it to happen faster than planned.
She wrote on Monday that Pezzullo's revelations would be a shock to many of you, but urged her colleagues to continue working closely together on their 'critical' duties.
After his term ends, sources have said Pezzullo was in contention for a foreign post, with Brussels and NATO among the possible posts.