There were reports of a big meteorite crossing south-western New South Wales and central Victoria overnight.

Victorians from Geelong to Mildura called police after apparently watching the object.

Senior Victorian Constable Peter Bullock and his partner were patrolling the Calder Highway at Kyneton at about 11:20pm AEDT when they saw what they say was a huge light.

Senior Constable Bullock says they had a clear view of the meteorite dropping towards the ground in the eastern sky.

"My offsider with me had a look as well and we were just dazzled," he said.

"It was unbelievable, it was a huge light, much bigger than any star. It was sort of round and had a very long tail and seemed to be dropping fairly slowly, so we were able to see it for 15 to 20 seconds."

"I said to my offsider, 'that's a meteorite, it's certainly too big to be a falling star' and he said the same thing."