Investigator James Molesworth said a Stawell man reported the latest sighting at 5.

55am last Wednesday after seeing a `big, bright yellow light' heading from the east in a north-westerly direction.

Mr Molesworth said the man, keen to remain anonymous, was putting things in his car ready for work when he made the sighting.

"He normally keeps a camera in the car, but he'd taken it inside the night before," Mr Molesworth said.

"He watched it for about 45 seconds, then it did a looping turn and disappeared to the north-west within four seconds.

"This fits with other reports from the area."

Mr Molesworth said investigators had studied the Wartook Valley area from 2001.

His colleague Paul Norman has researched UFOs for 50 years and was joined in the Grampians study by Jacqueline Purtell. Mr Molesworth joined the team eight months ago.

"Since 2001 many sightings have been reported and investigated by VUFORS in the Grampians region," he said.

"These have included not just aerial lights at night, but numerous instances of craft being observed in daylight, sometimes at relatively close quarters, and a number of close and spectacular night time sightings.

"On top of this there have been countless observations made by VUFORS investigators and various locals connected to the investigation, usually of a rather less spectacular nature, but highly significant nonetheless.

"Video and photographic evidence has been collected in many instances."

Mr Molesworth provided the Mail-Times with detailed recounts of sightings since April.

"One group of people were driving past the national park in a car. I don't know where they were, but on the edge, when they saw a large yellow light appear from the trees and do an erratic manoeuvre," he said.

"Earlier this year, about five months ago, there was a sighting on Mount Victory Road.

"I saw some myself, a red and green flashing light moving around Mount Thackeray in the Victoria Range.

"In another sighting a few months ago now, a couple in the Victoria Valley saw five lights flying circles around each other and they got to Mt Thackeray and disappeared."

Mr Molesworth said people reported only 10 per cent of sightings.

"We don't get a lot of reports but a lot of people have seen things particularly in the Wartook Valley," he said.

Police at Stawell said they had received no reports about Wednesday's incident.

•Mr Molesworth said people could call 9808 6214 to report a sighting.