A closed-door hearing by Oulu District Court Thursday afternoon remanded a 17 year-old male in custody on suspicion of the rape of a 14 year-old girl in Kempele near Oulu on Monday.
The suspect is being held on suspicion of aggravated rape and aggravated sexual abuse of a minor. He is described as a foreign national..
Police said Wednesday that preliminary investigations revealed that a second person detained for questioning was not involved in the incident and was released.
The deadline for filing charges in the case is next February.
This preliminary investigation is unorthodox because the suspect did not commit a crime in Finland and is not a Finnish citizen, but is suspected of terror offences in Ukraine.
Finland's Foreign Minister says she trusts China to help conduct a thorough and transparent investigation.
With the 60-year confidentiality period lifted, the files offer insights into Oswald's mysterious stay in Helsinki before he visited the Soviet Union.