nothing dodgy

i want to locate my landlord without going through the estate agents

i’ve tried land registry (he’s listed at our address)

The estate agents are obligated to give you a contact address, no matter what they say.
you don’t have to tell them why you need to know

SA – where did you get this info? i ask so i can quote a reference to the estate agent

Its just stuff i know 😉

here is a link
http://england.shelter.org.uk/get_advice/renting_and_leasehold/rights_and_responsibilities/landlords_responsibilities#5

There is legislation about it, but i guess you don’t want all of that. I would just phone up the letting agents and ask them first. A lot of landlords instruct the letting agent that they don’t want any contact, so you may find that they won’t give details.