THE Archdeacon of Boston, responsible for two Lincolnshire churches from which more than two tonnes of lead was stolen, has described her despair at the theft. The Archdeacon, the Ven. Justine Allain Chapman, spoke of the "unbearable burden" of maintaining and churches such as St Peter and St Paul, Algarkirk, and St Mary's, Frampton, and protecting them from lead thieves.

Dr Allain Chapman, who oversees churches in South Holland, Bourne, and the Deepings, said: "It is a constant struggle to maintain these vast and beautiful medieval buildings. We have been looking at, and testing, various security measures . . . as the taking of roofing materials causes not only huge financial and administrative burdens, but diverts funds and energy away from serving the local communities."

The new technology with which police are trying to trace the stolen lead is being tried out at St Peter & St Paul. The managing director of Trace-in-Metal, which has developed the technology, John Minary, said: "A proportion of the lead from St Peter and St Paul has been infused with thousands of heat-resistant coded microdots, which means the lead will be traced back to the church.

"The microdots will survive the temperatures used to recycle lead, as they are both painted on to the surface of the lead, and infused into the lead sheet itself. The lead is also marked with the postcode of the church, PE20 2HH, and has mini-labels attached, indicating that the lead is indelibly marked.

"It is important to stress that these markers will survive extreme heat." The presence of the markers and the postcode can be found simply by using an ultra-violet torch, Mr Minary said.

"This is a test case for us, because it is the first occasion on which we've had any lead with coded microdots stolen. We have alerts out all over the country to look for this lead . . . it's simply a matter of finding the lead, tracing it back to the source of the theft, and we'll have a strong evidence trail there."

The Historic Churches' Support Officer for the diocese of Lincoln, Matthew Godfrey, said: "Hopefully, this new technology will prove to be a very good deterrent."

Mr Minary said: "Both the Grade I listed churches have received sizeable grants to carry out vital restoration work: St Peter & St Paul received £175,000 from the Heritage Lottery Fund; and St Mary's had £46,300 from the Listed Places of Worship Roof Repair Fund."

Police are also relying on the Scrap Metal Dealers Act 2013 which makes it harder for thieves to sell on stolen metal. Scrap-metal dealers who buy and sell for cash now face fines of up to £5000 under the Act, which also requires them to record and keep details of the name and address of the seller.

When the law was introduced, the Crime Prevention Minister Jeremy Browne said: "Metal theft costs the UK economy around £220 million a year, and it has a huge impact on our communities."