UK Fault with ring main

[Rubberhead]

I was testing a consumer unit before upgrading to current standards. (Old re wireable fuses) when testing one of the ring mains continuity i found 38v on the cpc with that circuit disconnected. After carrying out end to end tests on Line and neutral which came back fine. I found the voltage dissapared when I removed the fuse for the lighting circuit?
Any advice on what this would be?

I also have continuity between neutral and line on a leg but haven't had time to investigate further, i e splitting the ring.
Thanks in advance

 

[Dave OCD]

Used a mcb and powered it from the rfc rcbo?

Very close mate, but DPG hit the nail on the head.

 

[MJPD29]

I was testing a consumer unit before upgrading to current standards. (Old re wireable fuses) when testing one of the ring mains continuity i found 38v on the cpc with that circuit disconnected. After carrying out end to end tests on Line and neutral which came back fine. I found the voltage dissapared when I removed the fuse for the lighting circuit?
Any advice on what this would be?

I also have continuity between neutral and line on a leg but haven't had time to investigate further, i e splitting the ring.
Thanks in advance

L-n load could be anything, even a neon on a spur. Are you new to testing?