The five carcasses of the elephants that were found in the Mahaweli marshes in Polonnaruwa have been removed by the Department of Wildlife to carry out a post-mortem.
The post-mortem is to be held at the Giritale Wildlife Training Centre.
According to environmentalist sources, the five elephants had become bogged down in a marshy area near a tributary of the Mahaweli River in the Periyaaru region in Polonnaruwa.
The group of elephants included calves and a tusker.
Sources say that both tusks of the tusker had been removed by poachers.
Environmentalists assert they are awaiting the report of the post-mortem to ascertain whether foul play was involved in the death of these elephants.
The initial discovery had been made by a fisherman who had alerted authorities on 28 August of an elephant calf that had been entrapped in the swamp.
The bodies of four other elephants had surfaced on Saturday, bringing the total body count to five.