Ishiang Shih reportedly used his research position at the school to obtain integrated circuits used in US military radar, jammers and scramblers. The computer chips are at the centre of FBI accusations against his brother Yi-Chi Shih.

"I don't have any comment," Ishiang Shih told AFP Thursday.

Earlier he told Montreal's daily La Presse he had purchased the circuits for research purposes. "I was writing an application for a research grant," he said.

Last Friday, his brother Yi-Chi Shih was arrested by the FBI on charges of scheming "to illegally obtain technology and integrated circuits with military applications that were exported to a Chinese company without the required export license."

The computer chips had allegedly been shipped to Chengdu GaStone Technology Company (CGTC) in Chengdu, China.

The company was blacklisted in 2014, according to the US Attorney's Office, "due to its involvement in activities contrary to the national security and foreign policy interest of the United States -- specifically, that it had been involved in the illicit procurement of commodities and technologies for unauthorized military end use in China."

At the same time, Canadian federal police raided the offices of JYS Technologies in a suburb of Montreal. The company is solely owned by Ishiang Shih and his wife.

According to FBI documents, JYI Technologies had transferred Can$800,000 to a company set up by an alleged accomplice of Yi-Chi Shih in order to legally buy the so-called monolithic microwave integrated circuits or MMIC in the United States.

A sample of the circuits was also sent to Ishiang Shih's Montreal lab.

The technology, US attorney Nicola Hanna said, "could be used to provide companies (in China) with significant advantages that would compromise US business interests.

"The very sensitive information would also benefit foreign adversaries who could use the technology to further or develop military applications that would be detrimental to our national security."