OTTAWA - Federal ministers have been warned by their boss against subverting Canada's freedom-of-information law after a political aide at Public Works ordered a sensitive document withheld from a media requester.

"Obviously, around Access to Information, due diligence is and should be done by public servants and not political staff," Dimitri Soudas, spokesman for the prime minister, said in an interview Monday.

"The process . . . should be followed and respected by all. . . . It applies to everybody across government (including) political offices."

Last July, a Public Works bureaucrat was ordered to retrieve a 137-page report from the department mailroom after an aide to then-Public Works minister Christian Paradis discovered the document was being sent to The Canadian Press.

The news agency requested the report, an accounting of the government's real-estate portfolio, under the Access to Information Act and duly paid photocopy fees of $27.40.

But Paradis aide Sebastien Togneri sent an terse email to officials July 27 demanding that they "unrelease" it.

The bureaucrats were ordered to provide only a single chapter of the report, amounting to 30 pages.

"Only Section 11 should be released and not any of the rest of the document," Togneri demanded.

For the next three months, senior officials wrung their hands trying to prove to Togneri there was no legal basis for withholding any of the report, at one point getting a supportive opinion from Justice Department lawyers.

In the end, despite their better judgment, officials handed over the heavily pruned report to The Canadian Press without explanation. The fees were refunded. The file arrived 82 days later than the deadline under the law.

The news agency immediately complained to the information commissioner of Canada, which has since fast-tracked its investigation because of allegations of political interference.

Soudas declined to say whether ministers have been formally reminded not to interfere, or whether there will be repercussions to staff involved in the Public Works incident. "I don't comment on internal matters," he said.

Liberal Leader Michael Ignatieff called the episode an example of "the hold the PMO maintains on the access-to-information policy in this government.

"It shows how much a minister is controlled by a prime minister who does not like to give information to the press, to the public and to the opposition parties."

And Liberal MP Siobhan Coady called on acting Information Commissioner Suzanne Legault to widen her investigation to "all instances of Conservative interference and order the public release of all politically censored documents."

A spokesman for the British Columbia Freedom of Information and Privacy Association called the handling of the file "completely outrageous."

"This happens, we think, all the time," Vincent Gogolek said from Vancouver, adding it's rare there is an email trail to prove it.

Gogolek said the incident underlines the danger of "amberlighting," the process by which ministers' offices are kept abreast of potentially embarrassing freedom-of-information releases so they can prepare responses in advance.

"Once they start doing this, they're incapable of resisting the urge to fiddle with the actual request," he said.

A documented case of political interference happened a decade ago when the office of then-Public Works minister Alfonso Gagliano tried to thwart an Access to Information request for a report on the notorious sponsorship program.

At the time, the top bureaucrat in charge of Access to Information, Anita Lloyd, refused to co-operate and was later hailed as a hero for standing up to her political masters.

In the latest instance, the head of the Access to Information section in the same department was conciliatory, at least initially.

"How angry is the MO (minister's office)?" a senior official asked Tom Makichuk in an email on July 27, the same day Sebastien Togneri ordered the extraordinary mailroom recall.

"Somewhat," Makichuk replied. "Sebastien has a valid concern. . . . I'm finding for the middle ground."

Makichuk did not respond to requests for comment.

A spokeswoman for Paradis, who was shuffled to the Natural Resources portfolio last month, said the minister was not made aware of the request at the time.

Margaux Stastny also said Togneri was not trying to prevent release of the report, only to save the requester photocopy fees. She said Togneri merely wanted to offer the requester the choice between 30 free pages or the cost of photocopying 137 pages.

The Canadian Press was never offered the choice and, in any case, had already paid the fee.

Togneri has followed his minister to Natural Resources as director of parliamentary affairs.

Under the Access to Information Act, The Canadian Press obtained a 1,000-page file documenting how Public Works handled the earlier request.

A full version of the real-estate report that was initially censored shows, among other things, that the Public Works' portfolio has a 5.1 per cent vacancy rate, well above its target of 3.5 per cent. The full report was obtained through a later request.