Two Spencer residents were booked into Clay County Jail on Sunday, each charged with incest.
Jerrold Marble, 35, and Elizabeth Welch, 18, were each arrested and charged in the matter.
Spencer Police Chief Mark Lawson said Monday the investigation is ongoing and noted the involvement of the Department of Human Services in the case.
"That's all we can say at this time," Lawson said.
Additional details regarding the arrests will be provided once the investigation has been completed. Lawson anticipated it may take another week or two to finalize the details.