POLICE are appealing for people to help them convict stone flag thieves by reporting thefts.

Although police said they have made a number of arrests in the past, they have been unable to make any of the crimes stick due to lack of evidence.

"We arrest these men, but have to let them go because nobody reports the theft so we can't say for certain that they have been stolen," said PC Mark Pinder.

Five men were arrested at around midnight on Wednesday last week while driving a white H-registration Peugeot 205 in Whinney Hill Road, Clayton-le-Moors, with seven stone flags in the back.

They were released without charge because officers could not find anyone who had been the victim of stone flag thieves in the area.

The suspected theft is one of a rising number of stone flag robberies. In Hyndburn and Clitheroe, there have been 142 crimes.

Recently 45 historic stone flags were stolen from All Saints' Primary School, in Clayton-le-Moors. The "irreplaceable" stones dated from the 1840s when the old school building was built.

But PC Pinder believes this is just the tip of the iceberg, with many more going unreported.

Although the flags can be sold locally for only £10 a tonne, in the south of the country they can fetch £35 to £40 a tonne.

PC Pinder said: "It is really difficult to say that they have been stolen, even though we suspect they have been. What we ask is for people to come forward and report any theft, especially this latest one, so we can can make a case.

"We also ask people to have better security for flags because these people are lifting them in the day -- as bold as brass -- and people think they are workmen because they are wearing high-visibility jackets."

Police support officer Tracy Finn said: "We have a marking scheme underway in which residents, businesses and farmers can pick up an ultraviolet marker pen and mark their stones as they would their cycles or videos."

Phone police on 01254 353103, or go to your local police station.