LEWISTON — Police recovered human remains Tuesday at Casella Waste Systems on River Road after receiving a tip, authorities said.

Local police detectives along with Maine State Police interviewed witnesses and secured the scene, according to Shannon Moss, spokeswoman at the Maine Department of Public Safety. The site is next to the city’s solid waste facility and is owned by the city and leased to Casella.

She said the Office of the Chief Medical Examiner assisted with the collection of the remains as did members of the Maine State Police Evidence Response Team.

A postmortem examination of the remains is expected sometime in the coming days, Moss said.

Detectives and response team members were expected to remain at the scene most of the day Tuesday “investigating the circumstances surrounding this discovery,” according to Moss. Local and state detectives “continue interviewing witnesses and other persons of interest at this time.”

The call tipping off police to the remains came in shortly before 9 a.m.

Police stationed an officer at the entrance to the facility after it was closed for the investigation.

According to Moss, “The Maine State Police do not believe that there is any threat to the public and will share more information as it becomes available.”