Gardaí believe a man who was found dead in a camper van in the early hours of yesterday morning was strangled in a row in the vehicle just before his remains were found.
A man known to the victim was under arrest last night and may appear before the courts in relation to the murder as early as today.
Gardaí were called to the camper van at Lough Lene, Collinstown, Co Westmeath, shortly before 4am yesterday morning. When they arrived they found one man dead and another, believed to be his travelling companion, in a distressed and disorientated state.
The area was immediately sealed off and the State Pathologist, Prof Marie Cassidy, was informed. She carried out a preliminary examination of the remains on site and at first it was believed the dead man may have died as a result of a drugs overdose.
There were no physical marks on his body and the second man was not in a sufficiently lucid condition to assist the Garda's inquiry.
However, when a postmortem was carried out, it emerged the dead man had been manually strangled. The Garda's investigation was upgraded to a murder inquiry.
The dead man had not been officially named last night but was named by Garda sources as Thomas Canning (42), from Summerhill in Co Meath. His companion is a 28-year-old also from Meath.
They are believed to have parked their camper van at the site close to Lough Lene shortly after midnight yesterday. There were a number of other vans parked close by.
It is understood a row ensued in the early hours during which the dead man was fatally injured. His companion immediately alerted the emergency services.
This man was being questioned at Mullingar Garda station last night under Section 4 of the Criminal Justice Act. He initially received medical treatment at the Midland Regional Hospital, Mullingar, but was in a position to be interviewed by gardaí later in the day.
A woman who is believed to have been with the two men in the camper van yesterday assisted gardaí with their inquiries. However, she was not arrested.
Gardaí investigating the murder believe a number of other people were with the dead man, the suspect and the woman earlier on Wednesday night.
These had been traced yesterday and some have already spoken to gardaí. None was arrested.
The van in which the murder is believed to have taken place had already been the subject of a Garda investigation after it was reported stolen close to where it was later parked at Lough Lene.
The 28-year-old being held last night must be charged or released without charge by midday today. Garda sources said he may appear before the courts today but this was not confirmed last night.
Members of the Garda Technical Bureau carried out a full examination of the vehicle yesterday.