The use of fingerprint recognition technology to monitor retail staff working hours has serious privacy implications, say experts.

A small group of Budgens and Costcutter shops have introduced the system to monitor the hours worked by staff and to prevent staff clocking each other in.

The systems do not store the print itself, but log a number which can then be matched against the number generated next time that person clocks in.

But there are serious legal data protection implications, according to Gus Hosein, a digital privacy expert at the London School of Economics (LSE).

“The number is still a unique identifier,” he said. “It’s fine if people have a choice, but if you compel workers to do this, you run in to the dirty side of the law.”

The Information Commissioners Office (ICO) said Budgens’ use of the technology had practical advantages, but this did not alter staff perceptions.

“Given the association of fingerprinting with law enforcement and criminality people understandably tend to see the use of fingerprinting technology in other contexts as highly intrusive,” it said in a statement.

The retailers’ plans may raise issues regarding compliance with the Data Protection Act (DPA), said Vinod Bange, data privacy law expert at law firm Eversheds.

“The DPA framework requires that the employer justify that fingerprint technology is appropriate in the circumstance and must demonstrate why other less intrusive methods would not do the job,” he said.

A fingerprint technology project aimed at tracking travellers at Heathrow Terminal 5 was abandoned last month following pressure from the ICO.