Kent County Council has defended its use of so-called "spying" powers as the Government announces a review likely to curb their use.

Council chiefs insist they only use powers to carry out surveillance when absolutely necessary as part of investigations into serious offences that might otherwise go unpunished.

The Government says it is to review the use of the legislation amid rising public concern that some councils are using it inappropriately. Critics say the legislation - used by councils under laws designed to combat terrorism - amounts to a "snoopers’ charter."

Cllr Mike Hill (Con), KCC cabinet member for communities, said:

"We are very careful about using it and make sure that it is applied only when it is needed and that it is only applied by a small number of people who have been authorised to do so. We use it to crack down on rogue traders, flytippers and people suspected of counterfeiting. These are serious offences, not minor ones and are offences where we need to use the powers to get the prosecutions we need," he said.

Figures released under the Freedom of Information Act showed that KCC had used the powers 18 times in 2007. Investigations involved monitoring a warehouse suspected of selling fake toys and surveillance of someone suspected of cold calling to persuade people to have their driveways resurfaced. On one occasion, the law was used to check phone records 23 times.

In response to public unease, KCC agreed earlier this year to produce an annual report setting out how the legislation had been used.

Cllr Hill said: "The report will come to the council’s cabinet [its main decision-making body] so that we can assure ourselves that these powers are being used proportionately."

The Government wants to stop the powers being used for investigations into minor offences.

Home Secretary Jacqui Smith said authorities needed powers to protect people’s freedom "from interference by those who would do us harm".

But she added: "I don’t want to see these powers being used to target people for putting their bins out on the wrong day or for dog-fouling offences."

Local councils have also denied using the Act to target minor anti-social behaviour.

Ashford and Dover both said the use of such cameras had been reasonable.

Robert Bliss, Conservative leader of Shepway Council, said: “Our cameras are used for traffic problems, we can refer back to them on robberies and when people are attacked in the street. It’s a security thing.

“I do think people are abusing it a bit. There needs to be some strong guidelines. We need to look at this camera business quite seriously. We don’t want this police state attitude.”