UFO sightings in Australia are on the rise, and international studies indicate a growing number of 'closet believers' of extraterrestrial life, according to people who track such phenomena.

But people who come forward to report sightings are still pilloried by much of society.

The issue emerged again last week after a video of an alleged UFO sighting over the NSW south coast was posted on YouTube and raised a few sceptics' eyebrows.

It was no surprise to UFO investigator Doug Moffett, who has been delving into the authenticity of sightings across Australia for more than 20 years.

"That's the way it is usually treated in the media - like this fun topic to laugh at, rather than being treated as a scientific possibility," the Daily Telegraph quoted him as saying.

Moffett, part of the UFO Research NSW group, pointed to the fact that there were an estimated 100 billion stars in our galaxy and planets that were billions of years older than ours as reason enough to validate the search for extraterrestrial life.

"What I'm trying to achieve is for people to not knee-jerk dismiss things," he said.

Central Coast grandmother Jane Pooley hardly fits the stereotype of a UFO believer. But the 51-year-old says she saw one last week.

She described watching a craft with rotating lights moving silently above Brisbane Water, near where she lives - an area recognised as one of Australia's UFO hotspots.