Police have officially called off the search for the remains of three-month-old Lewis, who was lost when his mother, Helena Wright, fell from a clifftop with him and his older sister. Authorities are now investigating the incident as a murder-suicide.

Wright, a young mother originally from Estonia, fell from Cape Northumberland near Port MacDonnell on the morning of Monday, June 27. She was holding her two children, 23-month-old Hazel and three-month-old Lewis, at the time of the fall. Wright's Isuzu SUV was found at the clifftop with its engine still running.

She and Hazel were found at the base of the cape, but Lewis' remains have not been located. Limestone Coast officer in charge Superintendent Trent Cox confirmed on Tuesday that the search efforts for Lewis have concluded, stating that it is unlikely he will ever be found.

"The grim reality is he's unlikely now ever to be found," Superintendent Cox said. He added that police would still investigate any reports of washed-up material in the future but that no formal search effort is currently underway.

Superintendent Cox also addressed the online speculation surrounding the tragedy, urging the community to stop the spread of unverified information. "What I'd like to see happen is a lot of the community chatter that's going on social media to stop," he stated. "Where there are gaps in information where the community's not in possession of [that information], for that to be filled with the rubbish that we're seeing out there helps nobody and it's incredibly distressing I'm sure for Mr Wright and the extended family."

He emphasized the police's duty to provide factual information to the coroner and acknowledged that compiling this information takes time. South Australian Police previously revealed that Ms. Wright had visited the Mount Gambier Police Station just hours before the incident. Superintendent Cox indicated that the police force would review its actions following the investigation and would implement changes if necessary, without waiting for the coroner's inquest to conclude, which can take years.