"George \(dicegeorge\)" gurgled happily,
sounding much like they were saying:

a chap who owes me money and an apology has left his LDV van and reg doc
with me, how can i disable it so he cant come at night and drive it off?

I dont want to tamper with the ... fuel system...

Why not? It'd be the quickest and easiest way of disabling a diesel.

shrug
Just get a wheelclamp.