The agency that screens air travellers and their luggage is now providing advice on its website about flying with medical marijuana.

The Canadian Air Transport Security Authority says while no change in policy has been made, it has updated its website to inform passengers they should be prepared to show medical documentation if travelling with medicinal pot.

Passengers are also told that in airports where police officers are present, officers will be called over to verify the documents.

A spokesman says the advice was added to the CATSA website this week.

Robert Labbe says CATSA does not typically provide medication-specific information but decided that "marijuana is unique in nature and required further direction."

In airports without police presence, Labbe says a traveller's information is noted and passed on to local authorities before the traveller is allowed to continue.

He also says CATSA recommends that medical marijuana be packed in a passenger's carry-on luggage.

Banner photo: West Jet Airlines takes off from McCarran Airport in Las Vegas (Chris Parypa/Shutterstock).