In June Mr Jang was promoted to the post of vice-chairman of the National Defence Commission, the country's decision-making body.

ECONOMIST: North Korea's succession

Meanwhile, North Korea's new leader Kim Jong-un has been appointed "first chairman" of the country's top decision-making body, the National Defence Commission, state media say.

BBC: North Korea rocket launch fails

Mr Chang, who as head of domestic security runs North Korea's equivalent to the KGB, was elected to the powerful National Defence Commission (NDC) last year.

ECONOMIST: North Korea

Since Mr Jo is second-in-command to North Korea's leader, Kim Jong Il, on the country's National Defence Commission, this was America's chance to hear the next best thing to his master's voice on these pressing problems.

ECONOMIST: North Korea and America: Not yet at ease | The

"We had already warned the South Korean group of traitors not to make reckless remarks concerning the sinking of warship Cheonan of the puppet navy, " North Korea's National Defence Commission said in a statement, according to the Korean Central News Agency.

CNN: STORY HIGHLIGHTS

Canada's Globe and Mail newspaper reports that the Information Commission is investigating seven government departments: Environment, Fisheries and Oceans, Natural Resources, National Defence, the Treasury Board Secretariat, National Research Council of Canada and the Canadian Food Inspection Agency.

BBC: Has Canada's government been muzzling its scientists?

Canada's Globe and Mail newspaper reports that Canada's Information Commission is investigating seven government departments: Environment, Fisheries and Oceans, Natural Resources, National Defence, the Treasury Board Secretariat, National Research Council of Canada and the Canadian Food Inspection Agency.

BBC: Has Canada's government been muzzling its scientists?