That's the police's stated reason for refusing to provide a response to an OIA request electronicly, and instead only to provide it physically, on payment of a charge:
I'm sorry I can't forward this document to you electronically for security reasons. I can have it downloaded on to a disk - as per one of the options outlined in my letter.
This is simply bullshit. If there are valid security concerns - for example the report includes information about sensitive police methods or the suppressed identities of witnesses - then those are lawful reasons for withholding the information by redacting it. But having reached a decision to release, I don't think they can then decide to refuse to provide it in the requested format for arbitrary reasons like this.
Given the material requested - a report into the Police's handling of the Crewe murders, where police officers planted evidence to frame an innocent man - I suspect the "security" they're concerned about is the security of their deeply tarnished reputation. Sadly, their behaviour in this case simply makes it clearer that the police are still tainted by this scandal and refusing to admit wrongdoing for it. As for the solution, the Ombudsman should force them to release the information.
