The word "investigatory" refers to something that is related to investigations. It describes activities or processes that involve examining, exploring, or researching to gather information or find out the truth about a certain matter.
«We will ban the use of [surveillance] powers in the Regulation of Investigatory Powers Act (RIPA) by councils, unless they are signed off by a magistrate and required for stopping serious crime.» (politics.co.uk)
The plans suggest skipping the authorisation process by imposing an amendment on the Regulation of Investigatory Power Act. (politics.co.uk)
The committee called for a «root - and - branch» overhaul of the Regulation of Investigatory Powers Act 2000 (Ripa) which is the legal framework against which this intrusive state surveillance has taken place. (politics.co.uk)