Irchester case, as he added:
However, Mr Thurley said there was evidence that many of those who targeted historic monuments, including metaldetector users who dug up archaeologically rich sites looking for valuable artefacts, were "habitual" offenders.
He suggested that some thieves even trawled English Heritage's databases of protected sites looking for places likely to contain rich pickings.
"There is no disincentive. If you get a slap on the wrist, you just do it again," he said.In the case of Irchester the scheduling is unequivocal.