THIEVES have stolen £7,000 worth of lead flashing from ornate buildings in a town's park.

Now police are to use anti-theft "smart water" in a bid to stop the thefts.

The flashing was stolen from the roof of two buildings in Blackburn's Corporation Park, with the grand gateway entrance in Preston New Road worst affected.

Now in a bid to tackle the problem police are going to use a special invisible chemical to "tag" the valuable material and make it easy to track if they are stolen.

PC Paul Schofield said: "We have a serious problem with people taking lead tiles from the roof of the buildings in Corporation Park.

"The gateway in particular is very ornate and it is not just any old tiles. Because of its appearance only traditional materials are used.

"We hope that by using Smart Water and publicising the fact that the flashing has been security marked it will bring the problem to an end."

The product, which is manufactured by SmartWater Technology in Shropshire, can only be seen under an ultraviolet light. Its unique forensic fingerprint means that if items daubed with the product are stolen they can be traced back to their original location if found.

The manufacturers boast that Smart Water is "virtually impossible to completely remove".

In the past the product has been used in schools and businesses to security mark their property.

Last weekend flashing worth £1,000 was taken from the roof of the gatehouse. PC Schofield said theives returned this weekend and this time got away with £6,000 of the material.

He said: "Smart Water is ideal for the problem that we have here and hopefully it will work.

"As well as security marking the tiles there will be signposts put up warning potential thieves that the product has been used.

"It has worked at schools and businesses as a deterrent and we hope it will work here."

Anyone with information should call Blackburn police on 01254 51212 or Crimestoppers in confidence on 0800 555111.