Copenhagen - A Danish student journalist who was detained in Iran a week ago for allegedly working illegally returned to Denmark Wednesday following his release.

Niels Krogsgard, who is studying at the University of Southern Denmark, was arrested in Tehran on November 4 at a protest rally against Iranian President Mahmoud Ahmadinejad.

He told reporters at Copenhagen Airport that while in detention he was questioned about his sources in Iran.

Krogsgard, along with fellow Danish student, Henrik Fallesen, had been in the Islamic republic doing research for an essay on Iranian politics.

He said they planned to complete the essay.

Iranian authorities charged Krogsgard with carrying out journalistic activities without an official accreditation by the relevant foreign press department which is affiliated to the ministry of culture and Islamic guidance, according to a statement carried by the Fars news agency. (dpa)