The 12-year-old boy whose body was retrieved from the Presumpscot River was identified on Monday morning.

Rachsombath “Rex” Rasmey, of Portland, was reported missing on Sunday night after he went under and never resurfaced, Westbrook Police Chief Sean Lally said in a statement.

It wasn’t clear Monday how or why the boy got in the river and his family declined to talk about his death through a family friend.

Westbrook police and fire departments initially searched for Rachsombath around 4 p.m. Sunday at the Lincoln Street boat launch. Dive teams from the Portland Police Department and Maine Warden Service responded that evening and a warden service diver located the boy shortly after 7 p.m., Lally said.

Lifesaving measures by the Westbrook Fire Department were unsuccessful and the boy was pronounced dead at Maine Medical Center.

“Our hearts go out to the family and friends of the victim during this difficult time,” Lally said in the statement.

Rachsombath’s cause and manner of death will be determined by the Maine Office of Chief Medical Examiner.