A Sri Lankan national in Australia on a student visa with links to ISIS has been charged with terrorism-related offences in Sydney following an investigation by police and security agencies.

The man, 25, who police say was employed as a contractor at the University of New South Wales, was arrested by the NSW Joint Counter Terrorism Team at 2pm on Thursday afternoon at the university in Kensington.

Following inquiries, a search warrant was then executed at a unit on Defries Avenue in the inner eastern suburb of Zetland about 2am on Friday where a number of electronic items were seized.

Australian Federal Police Detective Superintendent Michael McTiernan told reporters on Friday  police allegedly found a notebook that named a number of locations and individuals that are “potential targets”.

“We will allege that this person was in possession of a document that was used in the preparation of air terrorism offence.”

“They are symbolic locations within Sydney.”

“The charge laid against this person are serious and significant and should not be underestimated.”

“We have both psychologists and investigators looking at that document to try to interpret the intent and capability, but that is in essence the offence that is before the court.”

Detective Superintendent McTiernan said the man, who they allege was operating on his own, had been in Australia for a number of years and had traveled several times recently.

He was not known to police and does not have any criminal history in Australia, police said, alleging that “any of the planning was into the future” with “no ongoing threat to the community”.

The investigation into the man’s activities began after police were handed a notebook by an employee of the university.

“At this stage he hasn’t been charged with being a member of a terrorist group. From documentation, he would affiliate with ISIS,” he said.

His visa was due to expire in September and he was allegedly in the process of making an application for a further visa.

The man was refused bail to appear at Waverley Local Court on Friday.

-with AAP