The network said the auditor found Redford's staff blocked others from flying by booking seats in advance and then removing passenger names before printing the flight manifest.
Merwan Saher's findings are in an internal report to the government obtained by CBC News, the network said.
It reported that Saher also concluded that Redford derived a personal benefit by taking her daughter on dozens of government flights and used a government plane for trips where there were commercial options.
Redford resigned as premier on March 23 ahead of a caucus revolt due in large part to her lavish spending.
A call for comment to Redford's constituency office Tuesday by The Canadian Press was not immediately returned.
The auditor's report says Redford and her former chief of staff denied any knowledge of the altered passenger lists, CBC News reported.
Redford told the auditor general she did not request the government planes, but the report notes that, in every case, the request came from the premier's office, the network said.
"We were told by [the premier's] office staff and multiple staff from the Department of Treasury Board and Finance that for certain flights the remaining seats available on the plane were blocked to restrict access to premier Redford on the aircraft," CBC News reported Saher's report as saying.
"The implications of this practice were that other government employees or elected officials would not have been able to travel on those aircraft."
It was Redford who, before she resigned, asked the auditor general to review the government's flight program.
Opposition parties were already calling last spring for the province to scrap its fleet of four turboprop planes. Premier Dave Hancock has said the planes are sometimes the best and only way for government officials to get into remote communities.
Flight records show Redford took her daughter, Sarah, on 50 flights on government aircraft, including for two weekends in Jasper. The records simply list "meetings with government officials.''
Shortly before her resignation, Redford admitted to flying her daughter and her daughter's friend around on a handful of flights and paid back the equivalent airfares. She also admitted taking a government plane to a family funeral in Vancouver and bringing a plane in to fly her back from a Palm Springs vacation.
She also paid back $45,000 spent on travel to and from South Africa for Nelson Mandela's funeral in December. Redford and her aide flew to Ottawa, where the premier joined the prime minister's entourage. Her aide, however, took a commercial flight to South Africa.
He and Redford returned to Alberta on another commercial flight so she could attend the swearing-in of her new cabinet.
CBC News said the auditor's review found she could have returned on the prime minister's plane in time for the swearing-in.