Villagers all over the region have been left scratching their own heads after the mysterious appearance of carved stone heads in Goathland on 18 September, which was reported exclusively in the Whitby Gazette.

Some of the heads have gone as suddenly as they arrived but all bear a riddle which has left the unwitting beneficiaries of the sculptures poring over encyclopedias and scouring the internet for clues.

So far everyone has drawn a blank on the meaning of "Twinkle, twinkle, like a star.

Does love flourish from afar?" – an epigram attached to each head.

The heads are in different carving styles and types of stone but are united by the riddle – and the fact all seem to have been delivered in the early hours.

A man has been captured by security cameras at the village post office in Braithwell, near Rotherham, which was left with three.

"People want to buy them," said Mike Hoyes, whose wife Valerie runs the post office in the village.

"They were left on the doorstep at 4.14am.

"A big man with longish hair drove up and had three on the back seat. I gave a copy of the CCTV to the police."

Since the Whitby Gazette reported last week on six carved heads which had turned up at Kilburn, near Thirsk, many more sightings have come to light.

Some have turned detective to try to crack the puzzle – artist George Griffiths had contacted York Minster's stoneyard in an effort to trace a mason's mark on the head left outside his home in Arthington, near Leeds, more than a month ago.

A fortnight later, a second arrived and he now is aware of two more heads deposited with neighbours.

Both of his have what looks like a mason's mark, as well as a "chirho" Christian symbol, but are made from different stone.

Stone heads also turned up at Collingham, near Wetherby, but in both cases they disappeared later the same day.

A couple who ate at the Forresters Arms hotel, where the largest Kilburn head was left, told staff of a similar mystery in their home village near Selby.