There was one problem when senior ministers and officials of Prime Minister Stephen Harper's government said they were unaware of reports that prisoners were being tortured in Afghan jails, including prisoners handed over to Afghan authorities by Canadian soldiers.

Both international and Canadian law require officials in a position of "superior responsibility" to know or try to find out what is happening if they are told or suspect that a war crime or crime against humanity is being committed or about to be committed.

The best known principle of international law that resulted from the Second World War came out of the trials of the German defendants: "I was just obeying orders" is not a defence.

A second, lesser known, defence is also not permitted. This came largely from the trials of senior Japanese officials after the Second World War. For someone in a position of responsibility, "I didn't know" is not a defence against an accusation of war crimes or crimes against humanity.

That second principle was largely a result of the inhuman treatment by the Japanese of Allied prisoners of war in the camps, including Canadians held by the Japanese in Hong Kong.

Ignorance no defence

The first post-war trial of Japanese commanders held by the Americans was the case of Japanese Gen. Tomoyuki Yamashita, who was governor general and commander-in-chief in the Philippines at the time U.S. forces recaptured the country. Gen. Douglas MacArthur had Yamashita tried for war crimes on the grounds that "he knew or should have known" of the crimes committed by his soldiers.

One of the charges against Yamashita involved a camp holding American prisoners of war that was just steps from Yamashita's headquarters. Yamashita claimed he didn't know what was happening in that POW camp.

Later investigations of Japanese war crimes showed that junior and mid-level officers, constrained by Japanese culture, often did not report atrocities to their commanding officers. While civilian officials, including Japanese cabinet members, claimed that they did not know what was happening in the POW camps, evidence at the Tokyo war crimes trial showed that the highest levels of Japanese civilian and military officials had meetings where the ill treatment of prisoners of war was discussed and approved.

It was acknowledged even in the Second World War trials that an operational military commander couldn't be fully aware of everything happening in the zone of command and control. In the years since the Second World War, the "should have known" has been tested in various situations in the Middle East, the "Dirty War" in Argentina and the civil wars in the former Yugoslavia.

It is now generally acknowledged that the "should have known" standard applies to war crimes, as in the charge against Yamashita, that "were extensive and widespread, both as to time and area."

Had reason to know

There is also a standard of "had reason to know," which compels officials to thoroughly investigate allegations (of not as "wide spread") war crimes once they are reported.

The1977 Protocol I, which is an addendum of the 1949 Geneva Conventions, holds superiors liable if they "had information enabling them to conclude" that war crimes were being committed.

The statute establishing the International Criminal Tribunal for the Former Yugoslavia held officials responsible if they failed to act on information they had "reason to know" about.

The Yugoslavia war crimes trials have established that superiors, whether civilian or military, who have sufficient information that criminal activity is happening cannot escape liability.

Quoting from a key case on the treatment of prisoners in the Bosnian-run Celebici prison camp, the trial concluded, "A superior must not remain wilfully blind to criminal acts, nor ignore information concerning offences that have been committed or are about to be committed."

Colvin reports

Canadian diplomat Richard Colvin filed reports between April 2006 and October 2007 outlining his concerns about the torture of detainees by Afghan authorities. Colvin said he copied his emails to about 70 high-ranking Canadian military and civilian officials.

At about the same time, in April 2007, the Globe and Mail newspaper published its own investigation into torture in Afghanistan. Prime Minister Stephen Harper responded, "We are not at the moment told of the problems are being reported in the papers today."

The Conservative government has dismissed Colvin's reports. Colvin's recent testimony to a parliamentary subcommittee "seemed dramatic, but under questioning it was revealed to be flimsy, inconsistent, unreliable," Laurie Hawn, parliamentary secretary to Defence Minister Peter MacKay told CBC News on Nov. 18. "[He] did not come across as credible."

There have been other reports in the media regarding torture by Afghan authorities, from non-government organizations and from other governments.

Colvin has said that his superior, David Mulroney, ordered Canadian diplomats not to file reports on paper regarding allegations of torture. Instead, the allegations were discussed over the telephone and apparently records were not taken.

So where does this leave the prime minister, his cabinet, David Mulroney and roughly 70 officials to whom Richard Colvin sent his reports.

Under international and Canadian law, it doesn't matter whether or not the senior levels of government thought Colvin's reports were "not credible." They were obliged to investigate the report and find out if it was credible.

Those officials, if not directly involved in the Afghanistan file, were still obliged by international and Canadian law to pass that information on to officials who could investigate and confirm whether or not that information was credible — and if it was credible, to act on it.

In addition, it appears that some of the information provided to the highest levels of the Canadian Forces and the government was found to be credible. As Gen. Walter Natynczyk noted when questioned after a security conference in Halifax on Nov. 22, 2009, Canadian officials have halted the transfer of prisoners to Afghanistan's intelligence service "more than one time" because of the possibility of torture.

The question now before the parliamentary subcommittee is whether Canadian officials acted when they should have, and if they acted on any subsequent reports that may have been filed.

It is clear that Colvin followed the letter and spirit of international and Canadian law in reporting his allegations of torture. Once those reports were filed, the Canadian officials were legally obliged to act on those reports.

As for looking the other way when the reports were filed, there is ample legal precedent over the past 60 years that shows those officials were obliged to read and act on the reports. If the officials say they were not aware of their obligations under Canadian and international law, then a principle older than the Second World War comes into play: "Ignorance of the law is no excuse."

At the same time, the media has reported that many members of the cabinet said they had not read the 2006 report from the Canadian embassy in Kabul that outlined widespread torture in Afghan prisons, even though international law requires them to read it.

Despite the letter of international law, it is highly unlikely that Canadian officials would ever be brought before a war crimes tribunal, where it could be alleged they had "reason to know" that prisoners transferred from Canadian to Afghan jurisdiction were being tortured. The Japanese complaint that tribunals are "victor's justice" still holds true.

Robin Rowland, a producer and photo editor with CBC News, has an interdisciplinary master's degree in the law and history of war crimes from York University and Osgoode Hall Law School. His thesis was on command ability and command responsibility, and he is the author of A River Kwai Story - The Sonkrai Tribunal, a book on Japanese war crimes.