Former Agent showing their client my property - opinion needed on way forward

Letting Agents

I was wondering what the right thing is here

I have a rental property and currently am looking for tenants and thus have it on the market through an agency and it is on all the usual websites

An agency i used 4 years ago contacted me a fortnight ago stating they had a client looking for a property like mine ( even though it didnt have the client's must haves). I just ignored it. Since then this week i got a call from this old agency asking if we could touch base as they feel they have the ability to get me tenants. I tried ot just not be rude and said we'll see. Today i have had a email stating that they had shown photos they had on file to prospective client and they wanted to view the property
To give some context - I changed agents years ago because my experience with them was not good ( late payments, low rental income, bad service) so not keen to be using them again. I don't plan to change agent as i get a good service from the current agency

Now my queries are as follows - is it legal to be showing people photos of my property that they are have no contract to be finding tenants. Additionally is there any data protection issues that they have breached by contacting me via mail / phone and email as well as showing them them photos? Can I ask them to remove all my details (including pictures)?