Officers are launching a fresh appeal for information about a horrific rape in Dublin last month.
The shocking assault happened in the Cookstown area of Tallaght in the early hours of Sunday, October 14, and officers are determined to catch the culprit.
A source explained: "The main concern here is that this brute is still out there -- the big fear is that he could strike again.
"The victim in this case has been very brave and has given gardai great help in their investigation.
"At this stage it is very important that the man is apprehended as quickly as possible."
The victim -- a foreign national aged 25 -- was left in fear for her life during the sickening hour-long ordeal when she was targeted by a man who spoke with a Dublin accent.
The traumatised woman required hospital treatment for extensive injuries after the disturbing incident which occurred while the victim was on her way home after a night out.
RTE's Crimecall will feature an aerial photograph tonight of the Cookstown area which will indicate the main areas in which the savage attack occurred.
The suspect is described as 5ft 7 to 5ft 8 tall and has a slim build.
He is thought to have a Dublin accent and his eyes are described as "light coloured." On the night of the rape, he was wearing a white zipped-up hoodie and Adidas tracksuit bottoms.
In this case, gardai used a system called VICLAS, the Violent Crime Linkage Analysis System, a computer programme developed by the Royal Canadian Mounted Police in the early 1990s to compare different crimes for similarities.
However it failed to link the sex attacker with any other similar crime.
Gardai said: "On October 14 a 25-year-old woman was on her way home from a party when a man sexually assaulted her. The woman was afraid for her life throughout the hour-long ordeal. The attack took place on the Cookstown Road in Tallaght, Dublin. We appeal for information."
Anyone with information should ring Tallaght Garda on 01 6666000 or the Garda Confidential Line 1800 666111.
Crimecall will be screened tonight at 10.15pm on RTE 1