Swedish authorities have charged a man with spying for China, on suspicion that he gathered information on Tibetans who had fled to Sweden.

Prosecutor Mats Ljungqvist says: "This is a very serious crime because spying affects very vulnerable people."

Ljungqvist said Thursday that such people "must be able to feel confident that they can freely use their constitutional freedoms, for example to protest against a regime without risking persecution or other abuse."

In a separate statement, Daniel Stenling of Sweden's security service SAPO says the man, who was not identified, was arrested Feb. 26 and had cooperated with police in other European countries.

Stenling added "cooperation is necessary in the fight against serious crimes such as spying on refugees."