In a bid to ascertain the full extent of the use of private email accounts for official business between Michael Gove and officials at the Department for Education, Labour has tabled questions to be asked in parliament.
The questions, posed by shadow education secretary Stephen Twigg, aim to discover whether any other controversial issues were discussed privately.
The ICO was asked to look into allegations that messages containing sensitive information were being kept away from the spotlight by the Department for Education's (DfE) own civil servants, as well as the public.
Information Commissioner Christopher Graham said: "It should not come as a surprise to public authorities to have the clarification that information held in private email accounts can be subject to Freedom of Information law if it relates to official business.
"This has always been the case - the Act covers all recorded information in any form.
"It came to light in September that this is a somewhat misunderstood aspect of the law and that further clarification was needed."
- Has the Secretary of State or his special advisers sought advice as to whether the deletion of private emails concerning Government business constituted a breach of Section 77 of the Freedom of Information Act?
- Did the Secretary of State or his special advisers discuss sacking DfE civil servants via unofficial email accounts and if so will he publish those emails?
- Were any free school applications and specifically the free school application by Katharine Birbalsingh discussed by the Secretary of State or his special advisers on an unofficial email account and will he now publish those emails?
- Did the Secretary of State or his special advisers discuss the cancellation of the Building Schools for the Future programme via unofficial email accounts and will he now publish those emails?
- Will the Secretary of State publish all emails relating to Government business using unofficial email accounts sent or received by him or his special advisers between May 2010 and the present date?