In three of the cases workers were able to access data they had no authority to use and in the fourth a worker who did have authority to access data used it inappropriately. The fifth case involves a worker accessing the Prison Service sentencing database, said a Home Office spokesman.
"Disciplinary action was taken that resulted in the dismissal of three of those people. A fourth resigned before the process of a charge of gross misconduct could be completed. Another was an employee at a private sector partner, who has been dismissed," said the spokesman.
The security breach has raised questions for some about the security of any database attached to identity cards, a major plank of current Government policy. "Plainly, centralising all of our identity data into one centralised register in the Home Office's control is going to expose our information to risk of abuse from staff," said Phil Booth, national co-ordinator of NO2ID, an anti-identity card pressure group.
"Many of the risks that attach are not so often about hacking from the outside but from the inside job, but this is something that the Home Office has completely and flatly denied throughout the process and said 'we'll have security protocols in place and procedures to stop this'," said Booth. "They've claimed this for other databases as well and yet we have highly publicised cases such as the chap at the DVLA who was passing information to [animal rights groups] not just a few times but over 13 months."
The Home Office spokesman said that remaining staff at the IPS have been warned about unauthorised access. "The IPS takes its security very, very seriously and has reminded staff that any breaches will involve a charge of gross misconduct which will result in dismissal and that any offender will be liable to prosecution," he said.
The Home Office could not confirm at time of going to press whether or not any further legal action or a prosecution will follow the dismissals.
The information came to light following a parliamentary question from the Liberal Democrat Party. NO2ID says that it is compiling information on further potential for security breaches within the Home Office.
"NO2ID has been approached by a contractor at one of the companies tendering for the database for the ID card system who described to us how quite regularly he was able to break protocol and gain access to supposedly highly secure databases of another wing of the Home Office while on a job," said Booth.
The Home Office said that it could not comment without further details on the identity of the contracting company and the databases in question. Booth said that the group would not make those details public until later this week.