A Russian man lost 400,000 frequent flyer miles for sneaking a fat cat onto his flight.

Peter Kovalev/TASS (Photo by Peter Kovalev\TASS via Getty Images)

• Russian airline Aeroflot invalidated a customer's frequent flyer miles after he snuck his cat aboard a flight.
• The cat was too heavy to fly in the cabin and would have to be checked in the cargo hold, so the passenger found someone with a smaller but similar-looking cat, brought that one to check-in, and then switched the cats before going through security.
• He made a viral Facebook post, but the airline saw, and cancelled his frequent flyer account for violating the rules.
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A man's viral Facebook post celebrating how he snuck his obese feline onto his flight - even though the airline told him the fat cat wasn't fit enough to fly - may have just cost him more than an in-cabin pet fee.

Passenger Mikhail Galin wrote a Facebook post last week outlining the effort to bring his cat Viktor on board his Aeroflot flight from Latvia to his home in Vladivostok, in eastern Russia, transiting through Moscow.

The cat was weighed at check-in and found to be 10 kilograms, while the airline's weight limit for in-cabin pets was eight kilograms.

Galin didn't want to place his pet in the cargo hold, so he moved his flight to the next day, and decided to try and find someone with a "similar cat of a lower weight" in Moscow.

The next day when he returned to the airport, he brought a smaller cat, Phoebe, for the weigh-in. Meanwhile, Phoebe's owners held on to Viktor somewhere nearby but out of sight. After the weigh-in, Galin switched the cats, and checked in for his business class flight.

However, Aeroflot was less than amused, AFP reported.

It began an investigation, including reviewing security footage from the airport, according to AFP. It determined that Galin had broken airline rules with the ruse, and invalidated the 400,000 frequent flyer miles that Galin had accumulated over the years, AFP said.

"Aeroflot has taken the decision to take this passenger out of its frequent flyer programme," the airline told AFP. "All of the miles collected during his time in the programme will be annulled."

Neither Galin nor Aeroflot responded to Business Insider.