CALGARY -- Officials with an Edmonton-based, low-cost airline says physical distancing concerns on flights is the result of passengers electing not to pay a fee to ensure the seat beside them is empty.

A passenger on a recent Flair Airline flight from Calgary to Vancouver photographed a "completely packed" aircraft — with nearly all of the middle seats in the image occupied in the three-seat rows —  and shared her picture on Twitter.

The CEO of Flair Airlines says the passengers on the aircraft chose not to pay a premium to leave the seat next to them unoccupied.

"We're giving you a choice," Jim Scott told CTV News. "If you want to you can pay the extra $49 and have a seat next to you empty."

Several airlines have stopped filling the middle seats on their flights and Scott says Flair Airlines could adopt the same policy but the cost would be passed on to passengers.

"We would have to charge everyone one-third more and I think the customers that we carry don't have a lot of money. They're not rich people and they'll take the precautions and put the mask on to save that type of money."

Gabor Lukacs, an air passenger rights advocate, was shocked to see images of a crowded aircraft during the pandemic while safety measures are in place to reduce the potential spread of COVID-19 and questioned why the airline was able to fill the seats.

"I would be very troubled if airlines could pack people like sardines on board," said Lukacs. "It doesn't sound right to me."

In a statement to CTV News, Transport Canada officials confirmed that social distancing was listed as a key point for preventing the spread of the novel coronavirus in its guide that was issued to the aviation industry in May.

"Transport Canada encourages air operators to keep an additional space between passengers when seats are available and when safe to do so. As per Transport Canada’s COVID-19 Guidance for the Canadian Aviation Industry, air operators should develop guidance for spacing passengers aboard aircraft when possible to optimize physical distancing."

With files from CTV's Brenna Rose