New Zealand continually faces threats from espionage, sabotage, subversion and terrorism, the Security Intelligence Service says in its annual report.

The consequences of "realised threats" could include death, injury, very substantial property damage, compromise of government and private sector information and intellectual property.

The report for the year to June 2008, tabled in Parliament today, gives no details of the threats the country faces or where they come from.

It says those details have been omitted for security reasons.

"The service's targets continue to offer us new challenges," Director of Security Warren Tucker said.

"By and large they are pretty inventive.

"And the external environment -- the opportunities and threats posed not just by the targets themselves but by the changing world we operate in -- means we need to think about improving all the time."

The report says the SIS worked with the police on "various investigations" during the year under review when there was an overlap between intelligence and law enforcement.

During the year there were 25 domestic interception warrants in force and 14 of them were issued in the 12 months to June 2008.

The other 11 were issued during the previous year but remained in force for some part of the year under review.

"The methods of interception and seizure used were listening devices and the copying of documents," the report said.

"The information obtained materially contributed to the detection of activities prejudicial to security."