Police say a passerby found an elderly man dead in the Arnold Arboretum this evening.

The body had no signs of trauma on it, said Boston Police Officer Nicole Grant. The incident is being treated as a sudden death investigation.

Police were called to Bussey and South streets at 6:50 p.m. for the incident, though the police report that would say where in the Arboretum the body was found has not come in, Grant said.

Journalist Joe Battenfeld reported on Twitter that he had seen the body and that it was on the Peters Hill side of the Arboretum.