The attack, which was said to be contained quickly, is not considered high risk to those affected
Over 607,000 records have been leaked in a cyber attack on the Department for Education (DfE) in England.
The data, which has been shared on the dark web, includes telephone numbers and email addresses relating to individuals and organisations.
The figure represents the total number of records affected, not individuals.
The DfE said it is working closely with the National Cyber Security Centre and the National Crime Agency (NCA) to investigate the issue.
The attack, which was said to be contained quickly, is not considered high risk to those affected.
One of the major programmes affected was the Turing Scheme portal, which provides funding for international education.
The DfE has referred itself to the Information Commissioner's Office.
A DfE spokesman said: "We have robust processes in place to protect information and took swift action to contain this incident.
"The information involved is limited to customer service contact details relating to individuals and organisations. No other data has been accessed".
An NCA spokesman said: "We are aware of an incident affecting the Department for Education and are working with partners to understand the circumstances and impact."
Cyber attacks on government departments and public sector organisations are increasing.
Reports from major cybersecurity firms and bodies like the Microsoft Digital Defence Report note that the government sector remains one of the top three most heavily targeted areas worldwide.
The UK Government Cyber Action Plan estimates that roughly 28 per cent of the public tech estate relies on legacy technology, leaving departments heavily exposed.
In the education sector, around a quarter of institutions (24 per cent) reported experiencing a breach or attack at least weekly, according to the government's most recent Cyber Security Breaches Survey.
More than half of schools have reported an attack or breach in the last year.
