Drew DeVoursney, 36, of Atlanta and Francesca Matus, 52, of Toronto were reported missing last week, and their remains were found Monday in an "advanced state of decomposition," with DeVoursney's body on top of Matus', according to police.
Police have referred to the case as a murder investigation but have not released any more information about the two suspects detained or any possible motive behind the killings.
Police say the investigation is ongoing.
This is a breaking story. Please check back for updates.
ABC News' Radia Kirit and Anne Laurent contributed to this report.