The Identity and Passport Service (IPS) says it has dismissed 14 people over the last three years in relation to passport database abuses.
The IPS is now closely involved in building the government's national identity card database.
Of 16 cases where data protection is said to have been breached, all but one involved members of staff who had legitimate access to the Passport Application Support System database.
But those investigated were shown to have used this access for unauthorised checks not related to their duties. The other case involved a contractor misusing data.
In two cases, investigations did not lead to dismissal, leaving 14 staff being shown the door by the IPS.
The Home Office released the figures in response to a parliamentary written question from shadow home affairs minister James Brokenshire.
The figures show that the problem of unauthorised IPS database checks seems to be worsening.
In 2007-08, the IPS disciplined eight people, with seven being sacked. In 2006-07 it disciplined six and fired five, and in 2005-06 it disciplined and sacked two staff.
The released figures come at a sensitive time for the government, as it starts to issue national identity cards to foreigners from outside the European Economic Area, and gets ready to issue ID cards to workers in security sensitive areas such as airports next year.