A macklot's python is seen in a glass box filled with 50 deadly snakes outside O'Sheas Casino on the Las Vegas Strip in 2010 Ethan Miller/Getty Images

Passengers on an Alaskan commuter flight were in for a surprise after a startling discovery was made by a little boy clambering on his seat: a traveller on a previous journey had left his pet snake on board.

Luckily the reptile, which was partially covered by a duffel bag and estimated to be between four and five feet long, was sleeping and the crew on Ravn Alaska flight 7133 swiftly dealt with the situation to avert any panic.

Recounting the events, passenger Anna McConnaughy said: "He [the little boy] said, 'Oh, Mum, look at this. What's that?'

"That's how we figured out there was a snake sleeping in the corner," added McConnaughy.

Rather than rattling passengers, the snoozing reptile generated intrigue, with most people wanting to see the creature – which was not poisonous – rather than flee from it.

A pilot and flight attendant then discussed the best way to deal with the situation. "He [the pilot] said, 'I'll hold the bag, and you grab the snake,"' McConnaughy said. "Quite a gentleman."

The cabin crew member managed to clutch the snake by the belly and dropped it into a rubbish bag, which was placed in an overhead compartment. The plane reached its destination, Anchorage, on schedule.

An airline spokesman said the snake's owner had not registered the creature for cabin travel. He did, however, report that his snake was missing upon arrival at his destination.

In a statement to KTVA-TV, Ravn Alaska spokesman William Walsh said: "For the purpose of preserving cabin safety for the greater traveling public, Ravn Alaska prohibits all rodents, ferrets, reptiles, snakes, insects or any type of venomous or poisonous creature from being used as an emotional support animal."

It is unclear whether the snake's owner will face any charges.