Clergy who find respect for the cloth no longer shelters them from violence are to be offered a new device in the battle against crime a crucifix with an in-built alarm.

Avon Silversmiths, a British company, plans to introduce the product at the annual Christian Resources Exhibition in London next month. It will cost £169 sterling.

"It looks like an ordinary crucifix, but one tug will set it off and it's loud," designer Tony McCarthy has said.

One in three British clergy have been attacked in the course of their work, according to a survey commissioned for the exhibition.