For those (few) who would not have understood,
I meant of course that Hacienda can inspect all records showing an NIE, WHICH HAVE BEEN UP LOADED TO THE internet. (i do not know if when an accountant submits his/her ‘sign off’ report on company accounts for hacienda if the/she automatically posts that info. If they do then, that info would be available.
Hacienda have the right of access presumably by law, thus, do not need any court order (i.e. similar to The Bankers Book Evidence Act’s, which the police in UK use).
On one occasion when I was submitting my annual tax return in an Hacienda office, I had forgotten to include a small amount of interest I had received on a Spanish bank account. The inspector, said “No problem” and immediately accessed my couple bank accounts using my NIE. On another occassion, when making a denunicia at the National Police, having given them my NIE they accessed my personal records, full name, address etc, and included them in the report.
I also know (from professional experience) that Hacienda regularly exchange info on the internet with HMRC in UK. They have considerably more legal access to UK tax info than the police in UK have.