Town hall snoopers used controversial anti-terror powers to delve into the phone and email records of thousands of people last year.
They wanted to check for evidence of dog smuggling and storing petrol without permission – and even to trace a suspected bogus faith healer.
In one case they were inquiring into unburied animal carcasses.
Some councils are allowing middle-ranking staff to authorise covert operations under the controversial Regulation of Investigatory Powers Act, which is intended for use ‘in the interests of national security’.
Many of those spied upon will have no idea they have been subjected to surveillance, as those who are innocent have no right to know.
Last night Shadow Home Secretary David Davis said: ‘This is a stark demonstration of how the surveillance society has got out of control with the improper use of very broad powers – powers that the public would expect to be used only for serious crime and security threats.’
Using Freedom of Information laws, 152 local councils were asked if they were using the power to intercept details of who a person phoned or emailed plus when and where the call took place.
The answers revealed that town halls looked into the private data of 936 individuals and only 31 councils did not use these powers at all.
If the same pattern were repeated across the remaining 322 councils, it would make a totalof around 3,000 people having their phone and email records accessed by bureaucrats.
The Freedom of Information requests also revealed the range of offences councils have used the anti-terror law to probe.
Kent County Council carried out 23 telephone subscriber checks as part of probes into storing petrol without a licence and bringing a dog into the UK without putting it into quarantine.
Six of the 16 checks carried out by Sandwell Metropolitan Borough Council were intended to identify and locate a bogus faith healer.
Lewisham Borough Council’s 18 checks included six on a rogue removal firm and one on a rogue pharmacist.
Bolton Council requested subscriber details for a mobile phone number in connection with a probe into unburied animal carcasses.
Councils insist they are using the powers properly to investigate or prevent a crime. But opponents said it proves RIPA, passed in 2000 by Labour to regulate spying and surveillance by police and the security services, is far too widely drawn.
Civil rights group Liberty said: ‘You can care about serious crime and terrorism without throwing away our personal privacy with a snoopers’ charter. ‘The law must be reformed to require sign-off by judges, not self authorisation by over-zealous bureaucrats.’
RIPA also allows undercover council staff to watch individuals.
Operations can be justified on the grounds of anything from national security to ‘protecting public health or public safety’, ‘preventing a crime’ and ‘protecting the economic well-being of the UK’.
This can cover dog fouling and even putting out a sack of rubbish on the wrong day.
The latest findings follow a string of alarming examples of how the anti-terror power is being used.
Poole council in Dorset spied on a family because it wrongly suspected the parents of abusing rules on school catchment areas.