Mobile phone data is being used by Hertfordshire investigators to crack down on fraudsters and rogue traders, county councillors have heard.

Latest reports show that fraud investigators used communications data to identify social housing clients who had been sub-letting their properties in 2024/25.

And in the same 12-month period, trading standards officials used the data to build cases against rogue traders, leading to reimbursements for customers in excess of £100k.

County council investigators can apply to access mobile phone data under the Regulation of Investigatory Powers Act 2000 (RIPA).

And in 2024/25, council officials successfully applied to access communications data 66 times, compared to 43 authorisations granted in 2023/24.

Under the legislation, investigators cannot access the content of calls made or messages sent.

However, they can apply to access communications data on when and where a call was made, a message was sent, or an internet connection was accessed.

And on Tuesday (July 8), the use of the legislation was highlighted at a meeting of the county council's public health and community safety cabinet panel.

According to a report presented to members, mobile phone data was used in at least two investigations into the sub-letting of social housing last year (2024/25).

In one case, communications data placed a tenant at the social housing address twice, but at a different address 407 times.

When challenged, that tenant was reported to have admitted the offence and voluntarily terminated their tenancy.

"The keys were returned and the property was brought back into stock to be let to tenants more deserving of it," says the report.

In a second case, the report says the "heavy" usage of a communications mast that was not the most local to the social housing property provided "crucial evidence" for action to be taken.

The report says other techniques, such as access to banking records, would have "failed to identify the fraud".

In addition, trading standards officers are also reported to have used mobile phone data in the investigation of two alleged roofing fraud cases.

In a further example, the report highlights a vulnerable 80-year-old woman who contracted a trader to pave a pathway.

The work, says the report, expanded to include a driveway, work on a shed, and an installation of railings for £25,000, which the customer had said she had not agreed to and could not afford.

After unsuccessful attempts to meet the trader, trading standards officers used mobile phone data to trace the builder, who the report says had been using a false name.

At least once a year, county councillors have to review the use of the Regulation of Investigatory Powers Act 2000 (RIPA) legislation by council officials.

At the meeting, councillors were asked to note the report on the council's use of the RIPA legislation.

They were also asked to back policies in relation to directed surveillance and covert human intelligence sources, and to the acquisition and disclosure of communications data from communications service providers.

According to the report presented to the cabinet panel, directed surveillance was authorised under the legislation twice in 2024/25.

Both of these applications, according to the report, related to trading standards investigations into the alleged under-age sales of vapes, knives and alcohol.

In the first operation, test purchases were made at 14 premises, with one business selling a vape to under-age volunteers.

In the second operation, test purchases for alcohol and vapes were made at seven premises, with no businesses making sales.