The Southwest Finland District Court handed down a sealed ruling on Friday afternoon.
The court found the duo guilty on 11 counts of assault that took place between 2007 and 2009. Charges included aggravated rape, aiding and abetting aggravated rape and aggravated sexual abuse.
A statement issued by the court said the defendants were not convicted of crimes related to satanic worship, as suggested by earlier investigations.
An appeal is expected in the case.