Canada's special forces and elite counterterrorism units took secrecy too far and left their commanders — and sometimes the units themselves — in the dark about critical and occasionally deadly missions in Afghanistan, says the final report of a long-awaited closed-door board of inquiry.

The board was struck to examine the fallout from two separate military police investigations, one of which claimed Canadians turned a blind eye to alleged U.S. atrocities.

The inquiry concluded Canadian special forces also conducted too many "investigations internally, informally and superficially without the preparation of any reports of investigation."

A heavily-redacted copy of the report that came out of the multi-year internal military inquiry was released Wednesday to CBC News and the Toronto Star following an access to information request.

The board concluded members of the special forces units — including the elite Joint Task Force 2 — have had "an especially strong reluctance to report to someone outside of the core CANSOF (Canadian Special Operations Forces) community" and rarely consult with military lawyers when events are called into question.

The mere fact CANSOF claims something to be a matter of operational security does not necessarily make it so ... - Canadian Armed Forces board of inquiry report

The commander of Canada's special forces insisted Wednesday that the situation described by the report no longer exists — that special forces troops deployed in both Iraq and Niger have clearer, better reporting expectations.

"We took it to heart," said Maj.-Gen. Pete Dawe, referring to the inquiry's seven recommendations. "We learned from it tremendously."

A decade ago, military police launched an investigation into allegations made by a member of the Canadian special forces, who accused his colleagues of crimes as serious as murder.

The soldier claimed another special forces member, who was never identified, gunned down an Afghan man who was trying to surrender during a raid by coalition forces in 2006.

That investigation concluded with no charges, but morphed into a second, larger probe that examined a series of incidents between 2005 and 2009.

A second allegation surfaced — that U.S. forces, on a Canadian-led raid that may have taken place in 2006, executed an Afghan.

'Minimum amount of information'

Military police concluded in 2011 that there was no criminal wrongdoing by Canadian troops in that incident, but information about the conduct of U.S. special forces soldiers was passed along to American authorities.

The military board of inquiry, which interviewed 124 witnesses and collected 40,000 documents, was asked to look into potential failings of the system and the accountability of Canadian troops and their commanders.

The board examined a number of post-mission reports on raids in Afghanistan over the period in question — and while it found Canadian special forces units to be "highly disciplined" and respectful of the rules, it concluded they were providing the "minimum amount of information" to superiors.

The board concluded that the notion that special forces soldiers couldn't discuss what happened in the field outside of the unit was deeply ingrained.

While the board said in its report it is aware of the need for mission secrecy, "the mere fact CANSOF claims something to be a matter of operational security does not necessarily make it so."

All of the secrecy, said the report, "affected reporting on operational matters," even within the organization, and many members "relied exclusively on verbal reporting, with a tendency to report only minimal operational information using vague and imprecise language."

The result of that, said the inquiry report, was to leave senior commanders in the dark.

"The requirement for operational security was powerful enough to weaken [redacted] chain of command communications within the [special forces] rendering it ineffective when it mattered."

Government spent two years redacting the report

Dawe said verbal reports are no longer the routine among special forces units.

"There is a clear expectation and absolute clarity in terms of obligations and what kind of reporting needs to be done and to whom it needs to be done," he said.

The inquiry report was almost seven years in the making. It was completed and signed by the country's chief of the defence staff in 2016.

Brig.-Gen. Kevin Horgan, a senior member of the vice chief of the defence staff's office, said access to information officials have spent two years going over the document with a fine-tooth comb to produce a censored version for public consumption.

The military rarely releases the findings of boards of inquiry. It has, on occasion, made exceptions as it did in the investigation into the 2004 fatal fire aboard HMCS Chicoutimi.

Allegations rocked DND

The initial stories about the Sand Trap investigations were published and broadcast by CBC News in the fall of 2010.

A separate set of documents, also obtained under access to information, show the military launched a series of internal investigations to determine how much damage the release of information caused, particularly with Canada's allies.

An Oct. 18, 2010 memo from the then-commander of the special forces — retired lieutenant-general Mike Day— referenced multiple investigations by military police, the Canadian Forces Counter Intelligence Unit and special forces itself.

At the time, the military assessed there had been no damage to relations with American forces and other countries operating in Afghanistan.

With files from the CBC's Phil Ling