Kent Police is officially refusing to say whether it has devices capable of listening into people’s mobiles phones.
It was asked under Freedom of Information rules whether it uses the so-called Covert Communications Data Capture equipment, but refused to either confirm or deny its existence.
The force says releasing the information “could create a risk to national security or give criminals an insight into certain police tactics”.
Other forces have admitted they use Covert Communications Data Capture.
And in 2014, the Kent Police was discovered to have attempted to have accessed a journalist’s mobile phone records in the scandal involving former Lib Dem MP Chris Huhne in which his then wife fraudulently accepted penalty points for a speeding offence.
It had been attempting to identify the source of a Mail on Sunday story about the Huhne affair.
The Mail on Sunday subsequently accused police of “wrongfully” accessing innocent people’s information and said the law which allowed this to happen gave “officials frightening and near-totalitarian powers”.
In late 2016 Kent Police was asked under the Freedom of Information Act whether it had Covert Communications Data Capture, how it had used it and what promotional information it acquired ahead of purchasing it.
The force refused to answer and a complaint was later lodged with the Information Commissioner.
The commissioner ruled that Kent had been correct to withhold the information except the request concerning promotional information.
Adrian Futers, head of operational and information security at Kent Police, explained to the Canterbury Journal why it had adopted its position.
He said: “Under the terms of the Freedom of Information Act, police forces are entitled to withhold certain information if, for example, it is believed publication could create a risk to national security or give criminals an insight into certain police tactics.
“In this particular case we followed guidance from the National Police Chiefs’ Council in neither confirming nor denying whether Kent Police held information relating to the purchase of Covert Communications Data Capture (CCDC) equipment.
“Following an appeal by the applicant, the Information Commissioner ruled that we were entitled to do so under the sections of the Freedom of Information Act that relate to security bodies and national security.
“However, the ruling also states that we should have confirmed whether or not the force had received any marketing or promotional materials relating to CCDC equipment, and whether or not the force held any relevant legislation or codes of practice. These points will now be addressed in a subsequent response to the applicant.”