A senior Conservative peer has asked why official files about the Dunblane massacre will not be released until 2096.
Lord Tebbit raised the issues during questions in the House of Lords this afternoon.
Justice minister Lord Bach replied that he is "not in a position to say" why the files will be kept secret for so long, but added he will write to Lord Tebbit about the issue.
In March 1996 Thomas Hamilton entered the primary school in the small Scottish town of Dunblane and shot dead sixteen children and a teacher, before killing himself.
The incident was the deadliest single targeted mass murder of children in British history.
Lord Bach was answering question from Lib Dem peer Lord Lester about the recent decision to change the current law that public records are generally not be available for public inspection until they have been in existence for 30 years.
The government proposes to reduce that to 20 years and has tabled an amendment to the constitutional reform and governance bill to that effect.
Lord Lester said he "greatly welcomes" the change and hopes it becomes law before parliament goes into recess.
He questioned why the minister has rejected the need for extra resources to ensure the process will run smoothly.
Lord Bach said the bill is still before the Lords "so we will see what happens to it".
An impact assessment said the change will cost £50m to £80m over a ten year transition period, he told peers.
Lord Morgan (Lab) complained that the 30 year rule is already ignored by former ministers writing memoirs and that holding documents back contradicts the government's commitment to freedom of information.
Lord Bach said reducing the release date to 20 years would result in increased transparency and accountability.
He said the publication of memoirs by former ministers and others have been the subject of two recent reviews.
Lord Wallace (Lib Dem) said papers relating to defence, international relations and the economy are not covered by the current 30 year rule.
He asked if the government is concerned that the release of papers from 1910 might harm relations with Germany.
Lord Bach said it is "not quite as easy as that" and the exemptions under section 23, namely the security agencies and SOCA, do allow public interest releases.
However, papers that prejudice international relations or prevent the detection of crime will continue to be exempted from automatic release.
