Police are investigating a box containing bones and teeth that was discovered in the shed of a home. Tests by the state crime lab in in Missoula, Montana showed that the remains were human.
According to KHQ06, the bones were seen by an anthropology professor at the University of Montana who said that they were "likely modern and not archaeological" and belonged to three children aged between two and 10 years old.
The box was originally found in September by a cleaning crew brought in after the former tenants had vacated the property.
Further searches of the property in November threw up no additional evidence.
The Missoula Police Department had said there was a person of interest who they were seeking to interview but that there were no suspects in the case.
A search warrant stated that a person had been living illegally in a camper at the back of the house until summer 2016, The Missoulian reported.
The remains have now been handed to the national missing and unidentified persons system which will attempt to gather DNA that could be tested for matches in a database of known missing children.
Former residents of the city's South 12th Street have also been asked to come forward to speak with police.