Your name 
Your address
Contact details
Tenant name 
Tenant address

Date

Dear
Re:	Tenant address
I am writing to because it has come to my notice that during a recent visit to the above-mentioned property, it appeared that the locks have been changed.
It is important to the property security that I make sure that the home is secure and I must therefore ask you to contact me immediately to confirm if the locks have been changed and the reason the work took place.
I will also need to obtain a spare set of keys from yoy as soon as possible
Your cooperation is appreciated.
Yours sincerely

Landlord:	your name
Address for Service:  your address

Your address must be in England or Wales