An MP has revealed that over 600 staff at HM Revenue & Customs have been disciplined for snooping on tax payers' personal histories.
Treasury Financial Secretary Jane Kennedy said that 238 people were disciplined in 2005, 180 in 2006 and 192 in 2007.
While some employees received a reprimand, the MP revealed that a large number had been fired.
Kennedy said that HMRC has a "strict policy forbidding staff to access customer records unless they have a legitimate business need".
"Breaches of this policy are taken seriously and will result in the commencement of disciplinary proceedings," she said. "Each case is treated on its merits but, in many cases, the disciplinary penalty for breach is dismissal. "
The cases highlight continuing concerns about the department's competence in handling data on UK citizens.
Brian Spector, general manager at content protection firm Workshare, said: " You cannot force employees to stop accessing sensitive data. People are only human and mistakes are going to be made.
"Businesses need to deploy content protection solutions if they are to overcome human error and avoid the damaging consequences of data leakage.
"Technology should integrate itself into an organisation's people and processes, not the other way around."
