In rejecting an interview request from The Canadian Press, Correctional Service Canada said such access might pose a security risk or be disruptive, and would undermine his correctional plan.
"CSC has determined that your request to interview federal offender Omar Khadr cannot be granted," Kyle Lawlor, acting media relations and outreach adviser, said in the rejection email.
Khadr's lawyer, Dennis Edney, accused the government of hiding his client from the Canadian public to paint him in the worst possible light.
"There appears to be a propaganda value to ensuring that Omar Khadr is not seen other than as a terrorist," Edney said from Edmonton.
"It's important that the public get an understanding beyond how he's portrayed by the government."
The Toronto-born Khadr, 26, has been housed in the maximum security Millhaven Institution west of Kingston, Ont., since his transfer last September to Canada from Guantanamo Bay, where he had already spent 10 years behind bars.
Khadr had pleaded guilty before a widely discredited military commission in October 2010 to five war crimes — among them killing a U.S. special forces soldier — committed as a 15 year old in Afghanistan. He was given a further eight years behind bars.
Since then, American appeal courts have thrown out two similar military commission convictions — essentially because conduct cannot be criminalized retroactively — casting doubt on Khadr's conviction.
Most of those who have spent time with Khadr over the past decade — among them prison guards, lawyers and mental-health professionals — have described him as a gentle, non-radicalized and pleasant young man who is keen to get on with normal life.
One notable exception was U.S. psychiatrist Dr. Michael Welner, who acted for the military commission prosecution. He branded Khadr as a dangerous, unrepentant jihadist.
Edney said Canada is acting in the same way as authorities did at the U.S. naval prison in Cuba.
"Detainees such as Omar were never able to have visitors, speak to human rights organizations, or meet the press to publicly express who they were and the injustice of the imprisonment," Edney said.
"(Khadr) is a victim who suffered 10 years of horror in Guantanamo Bay, and the government continues to victimize him by keeping him in maximum security at Millhaven prison."
Canadian inmates may speak to journalists, although prison guidelines allow restrictions. In one example, B.C. serial killer Robert Pickton was granted one media interview before authorities barred further access to him.
Corrections refused to discuss the thinking behind the Khadr rejection.
However, Lawlor's email cites sections of "commissioner directive 022," which lays out conditions under which prison authorities may allow a journalist to talk to an inmate.
"It will not be contrary to the objectives of the offender's correctional plan," the section states.
A "correctional plan" is the approach prison authorities take with a prisoner with a view to his or her early release.
Also, a media interview may be granted if it can be done with "minimal disruption to the functioning of the operational unit and will not jeopardize the security of the operational unit or present a risk to the health and safety of any person."
Khadr is theoretically close to eligible for day parole and nudging toward full parole eligibility.
He has not made a release request, which would likely be denied given his classification as a maximum security inmate.