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Canada's former ambassador to the United States David MacNaughton.

Graham Hughes/The Canadian Press

Canada’s Ethics Commissioner has barred two federal cabinet ministers and seven senior officials from any official dealings with David MacNaughton for one year, after ruling that the former Canadian ambassador to the United States broke the Conflict of Interest Act.

Mr. MacNaughton was also the Ontario co-chair of the Liberal Party’s 2015 election campaign.

Ethics Commissioner Mario Dion issued the order on Wednesday. It requires Deputy Prime Minister Chrystia Freeland, Industry Minister Navdeep Bains, Chief of the Defence Staff General Jonathan Vance and others to restrict dealings with Mr. MacNaughton for a year.

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Mr. MacNaughton, who played a crucial role in the renegotiation of the North American free-trade agreement, left the envoy’s post in the summer of 2019 to join Palantir Technologies, a Silicon Valley company. He is the Toronto-based president of Palantir’s Canadian unit.

Palantir builds data-mining software for clients such as banks, manufacturers, pharmaceutical companies and government agencies, including law-enforcement and intelligence services.

Mr. Dion’s order said Mr. MacNaughton communicated with, or arranged, meetings with several public office holders for the purpose of offering unpaid assistance on behalf of Palantir to the government for its pandemic response. This included explaining what Palantir was doing to track COVID-19 in other jurisdictions, offering the company’s software to Ottawa for free.

The ethics watchdog listed 17 instances between March 2 and April 9 in which the Palantir executive communicated with or met federal officials, including Ms. Freeland, Mr. Bains, Gen. Vance and the other government officials listed in the order.

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The commissioner said Mr. MacNaughton has acknowledged “with the benefit of hindsight, that these communications and meetings, to the extent they could have furthered the interests of Palantir, were contrary to Section 33 of the act.”

This section prohibits former public officeholders from acting in a manner as to “to take improper advantage of his or her previous public office.”

The Ethics Commissioner said the communications with officials did not result in contracts for Palantir.

But, he ruled, “Mr. MacNaughton has contravened Section 33 of the act.”

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The list of people who are prohibited from official dealings with Mr. MacNaughton also includes Leslie Church, chief of staff to the Minister of Public Services and Procurement Canada; Ryan Dunn, chief of staff to the Minister of Innovation, Science and Industry; Simon Kennedy, deputy minister of Innovation, Science and Economic Development Canada; Bill Matthews, deputy minister of Public Services and Procurement Canada; Rick Theis, director of policy and cabinet affairs in the Prime Minister’s Office; and Jody Thomas, deputy minister of the Department of National Defence.

Mr. Dion did not indicate in his order why he set the period at one year.

Mr. MacNaughton did not immediately respond to a request for comment.

NDP ethics critic Charlie Angus filed a complaint about Mr. MacNaughton with the Ethics Commissioner in May after media reports that the former envoy had spoken to Canadian officials about how Palantir could help the government address COVID-19.

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Mr. Angus lauded the Ethics Commissioner’s decision on Wednesday. “It’s a good day for democracy in Canada.”

He said Parliamentarians should more closely scrutinize Palantir. “The fact they hired a very powerful Trudeau Liberal who had all the connections in Ottawa and Washington raises more questions.”

He said he was struck by how many powerful federal officials Mr. MacNaughton contacted in March and April. “This is literally a who’s who of the power structure in Ottawa.”

“We don’t want a company like this just walking in opening up the inside doors of power in Ottawa – we want accountability.”

Palantir’s software has been used by U.S. Immigration and Customs Enforcement (ICE) to track suspected illegal immigrants. The company was founded in 2003, in part with funding from the U.S. Central Intelligence Agency; its surveillance technology has been used in counterterrorism work, and Palantir reportedly played a role in the campaign to track down Osama bin Laden.

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“Our product is used, on occasion, to kill people,” chief executive officer Alex Karp told news website Axios in May. “If you’re looking for a terrorist in the world now, you’re probably using our government product and you’re probably doing the operation that takes out the person in another product we build.”

Banks such as JPMorgan Chase & Co. use Palantir’s software to spot fraud, while pharmaceutical companies use its products to sift through the results of drug trials or to track disease outbreaks. The company’s biggest customers are governments.

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