Lights problem with LED lamps not turning off

[Doomed]

Bungalow with loft conversion, DB 17th edition split load, so all circuits RCD protected.
Corridor has 3 wall lights, 2 on one switch, 2nd on its own switch. Also kitchen lights, lounge and living room on this circuit.
Customer fitted G9 (I think) LED lamps to hall fittings, and they don't fully turn off, always emitting a low glow. Checked voltage L to N and L to E and both read approx 60V. Interestingly the act of putting my fluke multimeter across the terminals to take a reading turned the LED lamps off - capacitor in the fluke?
Checked through the circuit as best as I could around the loft extension - small crawl space and lots of insulation - found several joints all on choc blocks for this circuit, by splitting them up I isolated the circuit to just the hall lights and the lounge lights, the cable then goes under the extension. The fault was still there - isolated the lounge off at the dimmer switch, fault still there.
Tried taking out the LED lamps - voltage still there.
Isolating the MCB removes the voltage.
Can't get to any more of the circuit, so any ideas where the stray voltage is coming from, or can I just fit something like a snubber and mask the problem?

 

[Doomed]

Sometimes you can get an induced voltage with two way switching, although 60 volts seems quite high. But even a small voltage can be enough to make low energy lamps glow. Sometimes dimable LED lamps won't glow like this.

The 2 fittings on the same switch(es) are two way switched - may disconnect the 2 way if easy when I go back to fit the bits on Thursday if I feel inclined and have the time to see if it helps out of interest.

 

[tamz]

Look for a borrowed neutral going to the extension.
I had the same problem in my house and asked every spark I knew why I was getting between 60 and 90v on the lighting neutral and they all came up with weird and wonderful ideas as to why and they were all wrong.
I was working on a job with a 3rd year apprentice spark and said to him and straight away he said you have a borrowed neutral. Hecalled up to the house and found it in 15 mins, pulled a couple of wires through (I just left him to it) and it was sorted.
I'm a plumber so will probably be banned and this post deleted by about half 9 tomorrow lol

 

[Doomed]

Get one of these
RC Contact Suppressor | Maplin - http://www.maplin.co.uk/p/rc-contact-suppressor-rg22y
and fit it across one of the lamps (where you put your Fluke multimeter).

Now fitted, problem gone, all happy - Thank you.

 

[D00DY_T00DY]

Why wouldn't you think the VD should count here? No difference in designing a 12V circuit to a 230V circuit. Albeit one is ELV.

You already have a 95% volt drop at the cu what's another 3?
I joke

 

[Marvo]

D-pole switches would also be an option if the neutral runs through the switch box