The German-speaking tourist from Liechtenstein became paranoid after drinking beer and smoking cannabis.

A​​ tourist from the tiny country of Liechtenstein should have thought twice before smoking New Zealand cannabis.

Simon Christopher Haas became paranoid and "haphazardly" sprayed his illegal pepper-spray at other travellers in an Arthur's Pass hostel dorm room.

Still feeling unsafe, he called police. He was the one who was arrested.

"Unfortunately, he smoked cannabis when he was not used to it. Maybe that says something about New Zealand cannabis," said defence counsel Nick Rout when Haas admitted one charge in the Christchurch District Court on Thursday.

Haas admitted a charge of possessing a disabling substance – the pepper-spray he had bought in Germany for protection while travelling in Australia and New Zealand.

Haas carried the spray through Australia without incident and brought it on to New Zealand knowing it was illegal, police prosecutor Sergeant Mark Berryman said.

At a hostel dormitory in Arthur's Pass on the evening of June 9, he consumed a small quantity of beer and cannabis, and at 1.50am the next morning "became paranoid about the other guests".

He pulled out the pepper-spray and sprayed it at the other people in the dormitory.

Rout said no-one was hit or hurt by the spray, which was done "haphazardly". No-one complained about it. Haas called the police because he still felt at risk, but ended up being arrested himself.

Haas had no other criminal convictions, Rout said.

Judge Tom Gilbert was told that Haas planned to leave New Zealand within a week. He imposed a fine of $600 and ordered the destruction of the pepper-spray.

Liechtenstein is a tiny principality 25km across, with a population in 2013 of 36,925. Lonely Planet describes it as "a pipsqueak of a country".