Russian passenger Yevgeny Kaymov posted footage of the incident online, saying he inadvertently recorded the odd behaviour of the flight attendant while on a business class flight to Dubai.
The incident has raised eyebrows over hygiene standards given that Emirates is widely considered to be one of the finest airlines in the world.
As some commenters pointed out, the flight attendant may not be pouring leftover champagne drank by someone else into the bottle.
Emirates airline is investigating a viral video posted online appearing to show a flight attendant pouring decanted champagne back into the bottle on-board a flight from Dubai to Barcelona in April.
'Actions recorded on this video do not comply with our quality standards.
He disagreed with another claim that workers were not allowed to pour liquids out while they're on the ground.
INSTAGRAMEmirates- the air hostess appeared to pour champagne back into the bottle in business class
Kayumov initially wrote in Russian in the description of his video asking Emirates directly why the flight attendant did not pour out the champagne that had not been consumed.
But although the video has cause a firestorm on social media, not everyone thinks the flight attendant is in the wrong.
One said: "I'm a flight attendant". I bet they're pouring it all back in the bottle so they can then pour it out at cruising instead of dumping it all in the trash can making it all soggy before takeoff.
An anonymous cabin crew columnist told The Independent that he thought she was likely conserving it. "We strive to consistently deliver the highest quality products and customer service".
Others commended the employee's thoughtful action. "We can't pour hot liquids out when we are parked at the gate, but I get rid of them by putting it in the toilet and flushing". "We are now investigating the incident", a spokesperson was quoted.
There is a slight (like 0.1%) chance the flight attendants will take this with them, depending on the Emirates policy (which I'm 99% certain would prohibit this), but otherwise this bottle is being disposed of and no passengers are drinking this.More news: Nokia 8 leak reveals Carl Zeiss dual-camera