National Crime Agency
The National Crime Agency (NCA) has been set up by the Home Office to tackle organised crime, defend the UK's borders, fight fraud and cyber crime and protect children.[1] 

The agency is not formally subject to FOI. See a relevant parliamentary ministerial answer.

The NCA website states: "To ensure we can protect our officers, victims, witnesses and partners the Freedom of Information Act 2000 does not apply to the NCA so we are unable to respond to Freedom of Information requests."