A Queenstown man has captured some mysterious footage above the Remarkables mountain range.
Matt Wilcox was out for a walk when he spotted something odd.
"[It] was probably only visible for around a minute or so. Then it went behind the Remarkables and out of sight."
Southland Astronomical Society astronomer Mike Bailey had examined the footage and said he believed it was not a plane because it was moving too fast.
"It also looks dirty, aircraft contrails would normally be white," he added.