Campers joined police to search through the night for the missing boy, who was last seen at a campsite at Thistledown Farm in Nympsfield, near Stroud at around 7pm last night.
Police said a more extensive hunt was due to start as daylight breaks.
More top news
The fourth batch of Bristol Shauns are rolled out at The Grand Appeal auction.
The third batch of Bristol Shauns are rolled out at The Grand Appeal auction.
A court has been shown CCTV footage of Nathan Matthews buying a circular saw from B&Q which he allegedly used to cut up her body.