Doris Lucas, 64, and Christine Pilcher, 57, were found to have made nearly £6,000 in total in false claims following separate investigations by Selby Council using a technique called data matching.

Data matching shows up apparent anomalies in the information held by public authorities and flags up the cases for further investigation. Targets often include someone found to be paying income tax and raking in social security at the same time or a "dead" person making claims.

In the Selby prosecutions the checks revealed the women were both earning undeclared interest on bank accounts. Pilcher, of Elston Place, Selby, failed to own up to having no less than five bank accounts, shares and a regular income from her ex-partner, the council said.

She produced documents to claim council tax benefit dishonestly between February 2002 and June 2006, by which time the size of the fraud had reached £4,413.

At Pontefract Magistrates' Court Pilcher was given a conditional discharge for one year and ordered to pay £250 solicitors' costs and £300 towards the cost of the investigation.

She was followed into the dock by Lucas, of Osgodby Nurseries, Cliffe Road, Osgodby, Selby, who admitted fraudulently claiming £1,510 in council tax benefit by failing to declare capital in a bank account.

The fraud lasted from January 2002 to August 2005. Lucas was given a conditional discharge for one year and ordered to pay £250 solicitors' fees and £200 towards the cost of the investigation.

In both cases Selby Council was alerted to irregularities in the claims when a national benefits data match was run. Early indications showed that Pilcher and Lucas were in receipt of hidden sums in interest payments. Further investigations were carried out and the relevant bank accounts were located.

Coun Gillian Ivey, who chairs Selby Council's social board, said: "The benefits system is in place to ensure that those people who genuinely need help can receive the financial support they require.

"But sometimes we find that people try and misuse the system. Selby Council takes the issue of benefit fraud extremely seriously because it impacts on all council tax payers.

"We'll continue to do all we can to track down and prosecute those people who give us false details or fraudulent information in order to claim benefits they're not entitled to."

Coun Ivey added: "I'd like to thank the benefit fraud team for their hard work in putting together the evidence in order to successfully prosecute in these two cases."

Data matching is part of the National Fraud Initiative and a value-for-money requirement of local government, NHS and the other public sector providers.

While designed to detect fraud it may also identify administrative errors or data kept on file which is wrong. Across the UK, almost 1,500 organisations supply around 4,500 sets of data in areas including housing benefit, payroll and pensions.

The data is cross matched to identify potential errors or fraud. From 2006-7, this can be done online via a secure website, making it easier for the organisations taking part to access the information and carry out their investigations. If anyone suspects benefit fraud in the Selby district, they can contact Selby District Council anonymously on 01757 292230.