Some material that was exfilitrated from the university's website has been placed on the dark web.
Contacted for comment, a Newcastle University spokesperson said: "The investigation into the incident is still at an early stage. IT colleagues continue to work hard on the systems recovery plan, and to support the Police and the National Crime Agency with their inquiries.
"However, we will not be able to share further detail on the incident until this initial investigation has concluded. The Information Commissioner's Office and Office for Students was notified within 72 hours of the cyber incident being detected."
"We take the security of our systems extremely seriously and we were able to respond quickly to this situation. Our IT team became aware of unusual activity on our systems on Sunday morning and immediately began their investigations.
"Our teams are working with a number of agencies including the police to address the current issues and are continuing to take measures to secure IT services.
"The nature of the problem means this is an on-going situation which we anticipate will take a number of weeks to address. A number of our IT services are not operating and will remain that way for the duration."