NEW DELHI, India: Canadian aviation authorities have asked Air India to investigate an incident in which a pilot was removed from a flight shortly before departure after being found under the influence of alcohol, according to a person familiar with the matter.

Two breathalyser tests carried out by Canadian police at Vancouver International Airport showed the pilot was unfit for duty, the person said on January 2. The incident was described as a "serious matter" by Transport Canada in a letter to Air India, and enforcement action is likely, the person added.

The source requested anonymity as they were not authorised to speak to the media. In a statement on January 3, Transport Canada said it would engage with Air India and India's aviation regulator to ensure "appropriate follow-up actions" are taken.

Air India said the Vancouver–Delhi flight on December 23 was delayed at the last minute due to the incident and that an alternate pilot was arranged to operate the service. The airline said Canadian authorities had raised concerns about the pilot's fitness for duty but did not provide further details.

"The pilot has been taken off flying duties during the process of enquiry. Air India maintains a zero-tolerance policy towards any violation of applicable rules and regulations," the airline said.

"Pending the outcome of the investigation, any confirmed violation will attract strict disciplinary action in line with company policy."

The aircraft involved was a Boeing 777, which can seat up to 344 passengers, according to the websites of Flightradar24 and Air India.

The letter from Transport Canada official Ajit Oommen asked Air India to submit its findings and details of steps taken to prevent similar incidents by January 26, the person familiar with the matter said.

The episode comes amid heightened scrutiny of Air India following the June 12 crash of a Boeing Dreamliner that killed 260 people. India's aviation regulator has since flagged multiple safety lapses at the airline, which was government-owned until 2022.

Pilots at Air India, now owned by Tata Group and Singapore Airlines, have also faced closer regulatory attention. Earlier this week, India's Directorate General of Civil Aviation issued warning notices to four Air India pilots, citing "serious safety concerns" related to regulatory compliance and flight crew decision-making.

According to the notices dated December 29 and seen by Reuters, the DGCA said the pilots had accepted an aircraft for operation last year despite prior knowledge of "repeated snags" and "existing systems degradations." The aircraft involved was a Boeing 787 used on long-haul routes, Flightradar24 data showed.

The DGCA has proposed tighter rules on alcohol testing for crew members, including a measure that would permanently revoke a pilot's licence after three positive tests. Under current Indian rules, post-flight breathalyser tests must be conducted at the first port of landing in India.

Canadian regulations prohibit pilots from operating an aircraft within 12 hours of consuming alcohol. Breaches can result in judicial or administrative enforcement action, including fines.