Central government departments across the UK have lost 150 computers to theft in the last six months.
It is unclear whether all the stolen PCs, mainly laptops, were protected by encryption software, which is available to all government departments.
Officials listed the number of thefts in response to a parliamentary question by Liberal Democrat MP Paul Burstow about incidents of computer hacking, fraud and theft in each department.
The Home Office, which takes the lead role in fighting terrorism, suffered the most computer thefts, with 95 machines stolen in the first six months of the year.
The Ministry of Defence reported 23 computer thefts, compared with more than 150 the previous year. MoD staff may now be more vigilant following a number of well-publicised laptop thefts from cars and bars suffered by senior military staff in recent years.
Peter Jaco, chief executive officer of encryption firm, BeCrypt, said, “If the affected government departments have followed recommended policies and implemented accredited solutions, all data on the machines would be protected as it would be encrypted to meet government security standards.”