Mr Christensen was dubbed the “Member for Manila” by colleagues after it emerged earlier this year he had taken at least 28 trips, spending almost 300 days in the Philippines between 2014 and 2018.
Several sources close to the probe have said the 41-year-old, first elected to the Queensland seat of Dawson in 2010, has frequently toured Angeles City, an urbanised area more than 80km north of the capital Manila which is known for its red-light district.
Marjorie Lamsen, the manager of one bar, Ponytails, claimed the federal politician was a “very regular visitor” at the venue.
Ms Lamsen, who said she had worked at the bar for six years, said: “He was always very good… He was a big spender”.
“It was well known that he went to other bars in the areas,” she told Nine News, The Age and The Herald.
“The weakness of George is women. He would usually give allowances to these people.
“He would keep his job a secret but now we know he’s a politician.”
The bar advertises itself as an “adult entertainment service” and says it employs 100 female dancers and 50 female wait staff.
Mr Christensen, a committed Christian, says he met his now-wife April Asuncion while in the Philippines in 2017.
Nine News, The Age and The Herald have seen documents which suggest Ms Asuncion was an employee at the Ponytails bar.
An employment card shows her listed as an entertainer at the venue.
The Balibago Barangay Social Hygiene Clinic confirmed the documents were legitimate but a letter from Mr Christensen’s lawyers on Monday said the documents were fraudulent and denied all claims.
Mr Christensen, who was re-elected in May with an 11.2 per cent swing towards him despite the controversy, has always labelled the scrutiny over his travels a “vile smear”.
The AFP looked into Mr Christensen’s travel for more than a year, including his visits to areas known for their active nightlife and bar districts.
Former prime minister Malcolm Turnbull received six briefings from then-commissioner Andrew Colvin after the former AFP boss directly raised the issue with the then-Department of Prime Minister and Cabinet secretary Martin Parkinson on September 7, 2017.
On coming to the leadership, Scott Morrison distanced himself from the excessive number of trips Mr Christensen took to the Philippines and said the travel ended when he became Prime Minister.
Deputy Prime Minister Michael McCormack, who was directly briefed by the AFP about its inquiries when he became Nationals leader in February 2018, had told Mr Christensen to stop travelling overseas and focus on his marginal electorate.
In April, Mr Colvin told an estimates hearing inquiries had found “no evidence of wrongdoing” and “no evidence of criminal behaviour”.
“So I want to be very careful and show the same respect I would show to any member of the public who has been found to have done nothing wrong,” he said.
In correspondence with Home Affairs Minister Peter Dutton in mid-2018, the AFP said it had finished its inquiries and was closing the case.
But several sources familiar with the probe said the letter had warned the MP could still be a target for “compromise by foreign interests”.
Anthony is foreign affairs and national security correspondent for The Sydney Morning Herald and The Age.
Rob Harris is the National Affairs Editor for The Sydney Morning Herald and The Age, based at Parliament House in Canberra