Kristy Nease · CBC News · Posted: Jul 20, 2026 4:00 AM EDT

Former federal scientist Dennis Lu, 65, was the subject of three briefings by the Canadian Security Intelligence Service (CSIS) to Lu's employer, Natural Resources Canada, according to court records. In May CSIS took the rare step of disclosing one of its own documents in court to set the record straight about how it came to be involved in the file.

The country's top spy agency says Natural Resources Canada approached it with concerns about former federal scientist Dennis Lu more than two decades ago, not the other way around — and has made a rare disclosure of one of its documents in court to set the record straight, CBC News has learned. 

There are also new details about part of the reason for a 23-month delay between the last Canadian Security Intelligence Service (CSIS) briefing about Lu to his employer in February 2021 and the start of Natural Resources' internal investigation into Lu in January 2023.

Lu's security clearance was eventually revoked and an RCMP investigation resulted in criminal charges of breach of trust and unauthorized use of a computer.

It's alleged that he used his access to the Natural Resources network to copy a total of more than 2,500 documents onto a USB key and external drive.

He faces trial in Ottawa's Superior Court by a judge alone in January.

This spring, a Department of Justice lawyer addressed court on behalf of CSIS "just to clarify" how the entire file on Lu began more than two decades ago.

"It wasn't CSIS flags per se, it was a government tip-off," Sheldon Leung said.

The lawyer's comments came during a pre-trial motion brought by Lu's defence team in its fight to access to hundreds of pages of third-party records that it said were relevant to the case — access it won for most of the documents.

Hosted Chinese delegation

Leung then read part of a CSIS document that the spy agency wanted the judge to see, dated Nov. 20, 2000 — the same year as CSIS's first briefing to Natural Resources about Lu.

"On Nov. 14, 2000, a source provided the following unsolicited information regarding a visiting delegation. According to source one, Mr. Dennis Lu, research scientist at [Natural Resources'] Advanced Combustion Technology branch (ACT), had invited a visiting Chinese delegation without the knowledge of his operational manager," the document reads.

"It was only after the fact, when questioned, that Lu provided the following information about the delegation to [his department's] security officials and his manager."

But Leung read no further, saying only that the rest of the CSIS document contained details about a meeting and some potentially sensitive government information.

This spring, a federal lawyer addressed court on behalf of the Canadian Security Intelligence Service 'just to clarify' how the entire file on Lu began more than two decades ago. (Sean Kilpatrick/The Canadian Press)

'Resource constraints'

During a separate pre-trial motion brought by the defence this summer about whether the investigation breached Lu's privacy, Brad Lanthier, a former chief security officer at Natural Resources, testified about the team he first joined in November 2022, 21 months after the last CSIS briefing about Lu.

Under examination-in-chief by assistant Crown attorney Tim Radcliffe, Lanthier said the team had recently been separated from the IT department and wasn't set up to take a large investigation on.

"There were severe, I would say, resource constraints in terms of our ability to conduct anything more than traditional risk investigations at that point in time," said Lanthier, now the RCMP's director general of national communications.

"It took a little bit of time [before the investigation formally began in January 2023]," he said. "The security function was just kind of getting up and going."

Lanthier testified that soon after he arrived, he was briefed about Canada's Task Force on Science and National Security, whose "primary goal was to safeguard science and to protect it from intellectual property theft, with a focus on foreign actor interference."

'A significant amount of risk'

He also learned about the Chinese government's Thousand Talents Program, which aims to bring scientists and researchers from all over the world to China, as well as the country's intelligence law, which can be used to compel citizens to share information with China to benefit its national security and economy.

As for Lu, Lanthier was told by colleagues that CSIS had briefed Natural Resources about him multiple times, that he was taking an extended leave without pay in China, and that he had asked his supervisors for permission to teach in China.

Taken together with the foreign interference threats from China, Lanthier said he believed there was "a significant amount of risk." So he asked IT staff to search Lu's emails for specific keywords, with CSIS providing input on what the search terms would be.

Lu was not granted permission to teach in China, and his access to Natural Resources' network was cut off while he was on leave because there would have been no need for him to access it, Lanthier told court.

Lu's access to Natural Resources Canada's network was cut off while Lu was in China during his leave of absence ahead of retirement, court heard.

Wrote MP to get network access back

Then Lu returned to Canada and asked for his network access to be reinstated — moves that were "surprising" to the federal department, Lanthier said, because Lu's original plan had been to transition into retirement during his leave in China.

Lu's request for network access was therefore denied, Lanthier said, and Lu's reaction to the denial raised further suspicions.

"I believe Mr. Lu used a few different avenues, including writing his MP, requesting his access back. At that point the risk [in my opinion] had escalated significantly given the travel, given the change in plans, and given the what appeared to be determined request to get access back," Lanthier testified.

"We were then informed that Mr. Lu had in fact amended his leave, so therefore, just like any employee, we had no choice but to give him his access back. But we did request [IT to conduct] daily activity reports [about] Mr. Lu."

He allegedly copied 2,414 documents off a Natural Resources shared server on July 7, 2023, and a further 188 documents on Aug. 9, 2023.

His security clearance was then revoked, Lanthier said.

Lanthier personally referred the case to the RCMP on Aug. 17, 2023. Based on "the sheer volume of files that had been transferred," Natural Resources then had to conduct a damage assessment to determine what was taken, whether it was of value, and whether other government departments would be affected, he said.

A USB key was one of two devices Lu allegedly used to copy Natural Resources documents off of the federal department's shared drive.

Searched 16 years of emails, phone use

In cross-examination, Reem Zaia, one of Lu's defence lawyers, pointed out that many countries have talent programs, including Canada, and that Canada's Policy on Sensitive Technology Research and Affiliations of Concern came into effect in May 2024 — almost a year after the documents were allegedly copied.

Lanthier acknowledged no evidence was found that Lu was a member of China's Thousand Talents Program and said he didn't know exactly what CSIS's concerns about Lu were — aside from affiliations with the Chinese government — when the investigation into Lu was ordered and conducted.

Zaia also read aloud part of a document outlining the testimony Lanthier had been expected to give, which said that "the fact-finding review [into Lu] identified some associations and correspondence with individuals from a country of a concern [China], but it was not definitive based on the narrow search conducted at the time."

That "narrow search," as Zaia pointed out and Lanthier acknowledged, included 16 years of Lu's work emails — received, sent and/or deleted — from January 2007 to 2023. It also covered all communications to and from his work cellphone — calls, messages and/or texts — across the same 16 years.

No instructions to exclude Lu's private information were made, court heard.

Co-operative agreements with China

Lanthier also didn't dispute that:

• Natural Resources security categorization standards allowed employees with security clearance such as Lu to store protected A-, B- and C-level documents on USB keys and external hard drives (A-level documents could cause injury to an individual, organization or government if compromised; B-level documents could cause serious injury; and C-level documents could cause extremely grave injury).
• A report found that about 1,100 Natural Resources employees were using USB keys in 2023.
• The standard operating procedure at Natural Resources allowed some staff 24/7 access to the federal department's network even if they had retired, according to a senior director of operations in an interview with RCMP. (Lanthier told Zaia he wasn't aware of that procedure, but had no reason to doubt it.)

He also wasn't aware that Natural Resources had a memorandum of understanding with China's National Energy Administration.

It took effect in June 2017, lasted five years, focused on energy, and "encouraged participants to promote technical and policy co-operation, including the exchange of experts and information as well as joint research," Zaia said.

Prime Minister Mark Carney, back left, and Premier of China Li Qiang, back right, look on as Minister of Energy and Natural Resources Tim Hodgson, front left, and Wang Hongzhi, Director of the National Energy Administration in China, front right, sign a memorandum of understanding to co-operate on energy in Beijing on Jan. 15, 2026.

(There had been a previous memorandum between Natural Resources and China's National Energy Administration regarding nuclear energy in 2014. A new memorandum between the departments to strengthen energy co-operation took effect in January this year.)

Pre-trial motions in Lu's case are ongoing. Four weeks have been set aside for Lu's trial next year.