The video, filmed over Los Angeles on Saturday, shows what has been described as an LA County Sheriffs helicopter checking out a hovering spherical object
It has been shared several times on social media and UFO and conspiracy theory websites and YouTube channel.
Tyler Glockner, who runs conspiracy theory YouTube channel Secureteam10, produced a video about the sighting.
In the short video he said a lot of people recorded it and saw it, which “validated the sighting.”
He said: “We have a police helicopter checking it out and circling it, which gives the impression they don’t know what it is.
“It is a mysterious, almost metallic sphere and is completely static.
“Is this possibly the best UFO sighting all year?”
He said he had ruled it out being a hot air balloon “because there was no basket.”
However, hopes that evidence of aliens may have been discovered above California, were soon dashed however, by sceptical debunkers.
The LASD aero bureau later confirmed what it was investigating.
The spherical object turned out to be an advertising helium balloon for vape company Brass Knuckles.
Scott Brando, who runs hoax busting website ufoofinterest.org, tweeted: “Object identified. As I said that #UFO filmed from #LosAngeles was an advertising balloon by “Brass Knuckles”.”
The Hoaxeye sceptical Twitter feed added: “Confirmed by the Los Angeles County Sheriff’s department aero bureau.”
Despite this, some of the original witnesses, did not believe the advertising balloon was what they saw.
Spike Karigan tweeted: “That Is in no way as big as the one I shot. This Is full of hot air, literally.”
Patco incorporated tweeted: “That is not the object filmed the other day. The object in question was silver. That balloon looks nothing like it.”