Police say the arrest and issuing of trespass notices to three University of Otago students was not part of an undercover operation.
Dunedin and Clutha area commander Inspector Dave Campbell said today the arrests were made after a complaint was received just after midday on July 16 thatpeople were smoking cannabis on the university's union lawn.
Plain-clothed police officers were sent to investigate and as a result of what they saw, uniformed officers were called in to arrest a suspect.
The plain-clothed officers were not working undercover and carried police identification.
Today the Otago Daily Times reported a poster naming undercover police officers who have been working on campus had appeared at the university.
Posters with pictures of plain-clothed officers working on campus and labelled "Narks in our Class?" and "Narkiology 101. How to spot a nark" went on display on Monday.
One poster showed plain-clothed officers involved in the arrest of three people at a National Organisation for the Reform of Marijuana Laws (Norml) stand at a Otago University Students' Association market day.
Mr Campbell said plain-clothed officers were often used to carry out observations when police believed criminal activity may be taking place and this policing technique often proved effective.
Police were only interested in those people who broke the law, he said.
Norml leader Abe Gray told the newspaper he was not sure who had put the posters together and posted them on the Norml website.
He thought the posters had probably been put together because students felt uncomfortable being under surveillance on campus.
Mr Campbell said police were running an operation to stop offences against the Misuse of Drugs Act on the university campus and, to date, as a result, had issued nine trespass notices to non-students and three to people enrolled at the university.
Those trespassers included known drug dealers, gang members or associates and one secondary school pupil.
The notices were issued by police acting as an agent of the university.
