How do i check that i still own land?

I have a parking space that shows on HM Land registry as being part of my property. A neighbour from an adjoining road states he can park there because in 2001 the treasury solicitor disclaimed the land and it passed into public ownership. I have owned the property since 1995 and have never heard of this. HM land registery shows that the land is still mine. How do i check what my neighbour is saying?