The 43-year-old Solum Larsen is suspected of having raped a 17-year-old member of the party’s youth wing after the local branch's annual conference in Suldal, south-western Norway, in early February.
He resigned from the Liberal Party (Venstre) and was admitted to a psychiatric ward at Stavanger University Hospital in the days after the scandal broke.
Prosecutor Elisabeth Rød said a decision would be taken later on Monday on whether Solum Larsen will face a remand hearing on Tuesday.
“The charges against him have not been altered after questioning,” she said.
Helge Solum Larsen has admitted to having sexual relations with the girl but continues to assert that she gave her consent.