The Garda Commissioner Martin Callinan is warning people to be careful about who they have contact with online.
He made the comment while updating reporters on the major garda investigation into the murder of Dublin woman, Elaine O’Hara.
Howerver Mr Callinan said however it was too early to speculate on whether or not Ms O'Hara made contact with her killer on the internet and warned that some of the speculation might not be helpful to their inquiries.
But he cautioned people about the use of the internet.
"The internet is a marvellous creation", the Commissioner said, "but I would tell people to know who you are dealing with and know the circumstances surrounding your business on the net. They should exercise reasonable caution and care, as in any other facet of life."
Gardai seem poised to launch a murder investigation into the the death of Elaine O'Hara.
Her partial remains were found in the Dublin mountains last Friday.
It emerged last night that a bag containing restraints and some of the 36 year olds personal belongings was found at Roundwood reservoir in Wicklow two days earlier.
Both scenes are still being examined today.
