Earth Tape? Any ideas?

Evening all,

I was at my sister's at the w/end and was looking at her earthing arrangement with a view to doing some minor work, and came across what looked like a TN-S system (the age of the installation, type of supply cable etc would back this up). On closer inspection I couldn't find an earth connection on the supply cable, but there is a metal tape connected to the CU MET which follows the run of the cable down to the floor but makes no connection with it that I can see!

I didn't have a tester with me to verify the earth, I was just wondering if any of you had seen anything like this before? I'm guessing that if it is the earthing conductor then it must be sweated onto the cable under the floor but this seems a bit odd, and guesswork isn't enough as we all know!

Surely not a lightning conductor in a three bed semi?????

You need equipment to verify Ze, I'm afraid.

I've got the gear, just didn't have it with me. I'm more interested in whether anyone has seen a means of earthing like this before.

I'll test it when I go back and take a pic, I know how much you all like them