A federal cabinet minister says he was subjected to a zealous security check at a U.S. airport last year, prompting Justin Trudeau's government to follow up with the Trump administration.

Minister of Innovation, Science and Economic Development Navdeep Bains said he was flying through the Detroit Metro Airport on his way back to Toronto with his Canadian passport following an economic summit with the Michigan governor back in April 2017.

Bains told the French-language newspaper La Presse that he had already passed through the airport's regular security checks, including a metal detector, when he was asked to do further tests.

He said the agent struggled with the swab test, read a false positive and then asked him to remove his turban.

Bains said he tried to stay calm and asked the agent if there was another option. In the Sikh religion, the turban is a mandatory piece of clothing.

"I will never be asked to take off my clothes. It's the same thing. It's a piece of linen," he said.

Another request to remove turban

He said the agent agreed to perform another test, which he passed, and he was allowed to continue to his boarding gate.

But then he alleges a security agent tracked him down at his gate, 20 minutes before takeoff, and said protocol hadn't been followed and he'd have to go back to security and remove his turban.

Innovation Minister Navdeep Bains spoke to reporters in Toronto on Thursday 1:12

That's when Bains said he flashed his diplomatic passport — and the agent backed off.

"I'm about to embark and you tell me to take off my turban. But, by knowing my diplomatic status, you tell me that everything is correct? This is not a satisfactory answer," he told La Presse.

Complaints to U.S. agencies

Bains said when he travels he doesn't like to reveal his cabinet position because he wants to see how things play out for people who aren't ministers or lawmakers.

He said the experience was unsettling and described the security agents as "very insistent and very difficult."

"It was very frustrating. It was unnecessary ... I felt very awkward," he told reporters in Toronto Thursday.

Bains said security is important but the incident "speaks to discrimination and discrimination happens with many people, and I'm in a very fortunate position to talk about it."

Bains's office said Global Affairs Canada reached out to U.S. officials and the undersecretaries for the Homeland Security and Transportation departments apologized verbally.

"I thought that was important for us to support Minister Bains, and frankly to support all Canadians travelling across the border," said Foreign Affairs Minister Chrystia Freeland.

"It was a conversation among officials."

Foreign Affairs Minister Chrystia Freeland weighs in on the trouble Minister of Innovation Navdeep Bains experienced while crossing the U.S. border. 0:35

In a statement to CBC, a spokesperson for the Transportation Security Administration said it reviewed closed-circuit video of the incident and determined the officer didn't follow standard operating procedures; the officer subsequently received additional training.

"We regret the screening experience did not meet the expectations of Mr. Bains," said Michael McCarthy.

"All persons wearing head coverings may be subject to additional security screening, which may include an officer-conducted or self-conducted pat-down. TSA does this to ensure that prohibited items or weapons are not concealed beneath any type of clothing and brought onto an aircraft. This policy covers all headwear and is not directed at any one particular item or group."

Bains said, for a Sikh, wearing a turban is considered "one of the most dutiful acts for a person of the faith and I am proud to represent my community."

U.S. needs to improve standards: Goodale

He said he's accepted the U.S. officials' apology.

"When possible, passengers may remove non-formfitting headwear before proceeding through the security checkpoint. We recognize that passengers may be unable or unwilling to remove items for religious, medical, or other reasons, and should expect to undergo additional screening protocols."

Public Safety Minister Ralph Goodale, who oversees border control on the Canadian side, said the U.S. needs to improve its standards.

"It's an unsettling incident and it's one that obviously the government of Canada wanted to draw to the attention of the U.S. administration, to demonstrate something that sometimes happens that should not happen," Goodale told reporters.