Lamp retaining mechanism
An anti-theft arrangement such as an anti-theft lamp with retaining means for securing it into a conventional lamp holder comprises a first part 102 adapted to engage with the lamp holder, a second part 104, a keyway 106 extending substantially through the second part into the first part, and a key 108 which, when inserted into the keyway, prevents any substantial rotation of the second part with respect to the first part. In the absence of the key, the first and second parts are relatively rotatable, preventing the lamp from being unscrewed. Preferably the first part and the second part of the anti-theft lamp retaining means are connected by means of a breakable connection (110, Fig 4A) so the lamp can be installed without needing the key and then rotated to break this. The invention extends to a complete lamp including an anti-theft retaining means, an adapter for a lamp including an ant-theft retaining means, and an anti­theft retaining means per se, such as for a variety of non-lighting items, such as CCTV cameras.