Northamptonshire Police says it is looking at information stored on electronic devices following its raid on Sixfields.
And the force also said fans should not expect a quick outcome from its investigation.
Acting Superintendent Paul Spicer said: “This remains a very complex investigation that is going to take a long time to work through.
“We are examining a significant amount of potential material [collected from Sixfields] to try to get to the bottom of what has happened.
“This includes examining a great deal of paperwork as well as information that has been stored electronically on computers, laptops and mobile phones.
“A number of detectives and officers from the hi-tech crime unit are currently involved in the investigation, and we are working closely with both Northampton Borough Council and Northampton Town Football Club, both of whom have co-operated with us fully.
“This is a live investigation and, therefore, it would be inappropriate to comment further at this time.”
Last Monday, Northamptonshire Police sent about a dozen officers to Sixfields stadium in response to a complaint of alleged financial irregularities surrounding the loan.
Mary Markham confirmed at the time the council had made “a formal complaint about potential financial mismanagement of funds lent to Northampton Town Football Club”.