A laptop has been stolen from St Albans District Council containing personal details on more than 14,000 local postal voters.

The information included the names, addresses, dates of birth and signatures of the 14,673 residents who applied for a postal vote in the June local election. The laptop was the fourth to be stolen from the council this month.

The council has said that the laptop did not contain details of votes cast, and was protected by two levels of security, according to reports in local paper the St Albans & Harpenden Review.

However, commentators have pointed out that, if the two levels of security are not strong enough, the personal data could be used for bank or credit card fraud.

Chris McIntosh, chief executive at hardware encryption specialist Stonewood, maintained that the data should have been encrypted, and that two layers of password protection will not put residents' minds at rest.

"We don't know what these two layers are, and if they're just simple log-in passwords then it is quite simply not good enough as they can be easily hacked, " he said.

"Organisations must start to understand the value of data and treat it accordingly. In cases like this where we are talking about personal data it must be encrypted to ensure that if a device is stolen the data cannot be accessed."

Data security firm CheckPoint suggested that the incident shows that organisations are overlooking the lessons of the past two years.

"In our recent survey of 135 public and private sector firms, over 50 per cent did not have any encryption in place to secure data on their laptops. This hasn't changed since the HMRC incident, so you have to wonder how many incidents it will take for the lessons to sink in," said Check Point northern Europe regional director Nick Lowe.