Gardaí are investigating whether a young girl witnessed the murder of teenager Cameron Reilly in County Louth.

A book of condolence has been opened in Dunleer following the 18-year-old's tragic death.

His body was discovered in a field in the Louth town early on Saturday morning.

He was last seen on a night out with over a dozen friends on Friday.

A post mortem revealed that he was strangled to death.

Gardaí are investigating reports that there were a number of young people present when he was murdered.

Editor with the Sunday World, Nicola Tallant, says the focus of the investigation is on Cameron's last few hours and who he may have been with.

"They have kind of narrowed it down to a very small group of people who they believe may have witnessed the murder, which was an assault and a strangulation," she said.

"There is indeed a juvenile girl who they believe was present."

Gardaí have appealed for anyone who was in Cameron's company, or knows anything about where he was on Friday evening and into the early hours of Saturday, to contact them.

They are also calling for taxi drivers, bus drivers or anyone with dash cam footage recorded in Dunleer to provide it to investigators.

Garda Inspector John O’Flaherty said investigators are attempting to locate Cameron's phone - a space grey iPhone 8 with a green hard back cover.

Garda Noel Loughran from Drogheda Garda station told LMFM that investigators are anxious to locate the device.

"It is an Apple iPhone 8; it is grey in colour and it has a green hardback cover," he said.

"We would ask residents and business owners in the area to check their bins in case Cameron's phone may have been left there.

"A phone had been found in the area but this phone is not connected with this investigation."

He said anyone with any information "no matter how trivial they think it is" should contact Gardaí in Dundalk or the Garda Confidential Line.