New analysis revealed by The Australian shows there was a 257 per cent increase in migration and refugee cases being reviewed by the Administrative Appeals Tribunal between July 2016 and August this year.
The data shows a surge in active appeal cases up to 62,476 from 17,480 over this period.
The Morrison government has defended the backlog saying it points to enhanced scrutiny and integrity within the system, with more permanent and temporary visa refusals behind this increase in appeals.
But a migration law analyst from Macquarie University Dr Daniel Ghezelbash is concerned the blowout could mean the opposite.
"When you don't have a properly functioning review process then it really strikes at the heart of the integrity of the visa processing system," he told SBS News.
"I think a lot of this is spin and the government trying to put gloss on what is going on."
The Morrison government has progressively taken steps to strengthen the vetting processes of migrant and refugee visas, including enhanced scrutiny and greater use of biometrics and intelligence.
There was a 46 per cent increase in visa refusals for the permanent migration program in 2017-18 compared with the previous year. This figure has remained stable in 2018-19.
Immigration Minister David Coleman said increased scrutiny in the vetting process had resulted in a rise in the number of visa refusals.
"Our vetting processes are much stronger than those in place under Labor and have seen an increase in the number of visas being refused. We make no apologies for this," he said.
"The Coalition will always run an immigration program that is focused on integrity and quality."
This increased scrutiny has seen the average refusal rate rise slightly across the temporary and permanent visa programs.
The figure has risen to 3.3 per cent of applicants being refused a visa in 2017-18, up from 2.5 per cent in 2015-16 and equates to 96,724 more applicants.
While, found 27 per cent of migrant and refugee applicants had their cases reviewed within 12 months of being lodged.
"The Coalition has restored integrity to our immigration program," Mr Coleman said.
The backlog figure of more than 60,000 visa applicants was on par with cases the Administrative Appeals Tribunal had on hand at the end of last year.
However, data does show the number of new applications lodged with the Administrative Appeals Tribunal continues to rise.
Visa appeals rose 76 per cent up to 3,286 last month from 1,867 in July 2016.
While the number of decisions made by the AAT almost doubled from 1,153 to 2021.
