'We Are Reviewing Your Benefit Claim'

Hello,

A few weeks ago I received a letter from the DWP stating:
'We will be visiting you at your home to talk about any changes that could affect your benefits'

Followed by:
'We will need you to provide us with the information on page 2 of this letter so we can make sure you are getting everything that you should'

I had to have statements of all my accounts for them to see and proof of ID. This week I had the visit. Before looking at my statements she told me that another government department had informed them that I had savings exceeding £6000. She then proceeded to glance over my statements and said that I was over. She noted down the details of my accounts and said that I would now need to provide statements of all my accounts dating back to when my current ESA award began, which is two years ago.

My concern, and question regarding this is: Is it possible for another (or any) government department to have access to my bank account details? I spoke to my bank and they told me under no circumstances would a bank divulge private bank details to any government department unless they had a court order. Was I lied to by the DWP worker?

Thank you Gordon, I had been looking how to do that but didn't see the option.