A "substantial" reward is to be offered for information leading to the return of the missing heart of Dublin's patron, Laurence O'Toole, stolen a week ago from Christ Church Cathedral.
Gardai are now trying to track down two men, who may be foreign nationals, who visited the cathedral last Saturday morning.
The men were wearing hats and avoided looking at CCTV cameras.
When they were asked to remove their hats they refused to do so, while one of them carried a backpack, garda sources said yesterday.
The men were in the cathedral between 10.30am and midday -- when gardai believe the theft of the ancient relic took place.
Gardai have been busy studying CCTV images from the cathedral itself and from surrounding businesses, shops and pubs.
When the men left the cathedral, one of them was carrying his backpack at knee-height and they were later seen running away from the building.
Gardai said they were enhancing video images of suspects and wanted to interview the men.
It is also likely that the thieves visited the cathedral previously to check out the security arrangements, as the heart was stolen from an iron-barred cage.
"The men on the camera footage could be crucial to our investigation and, at this stage, we are anxious to identify them, if only to eliminate them from our inquiries," one officer said.
More information on the reward and how it would be collected is expected to be released this
week.
But both cathedral staff and gardai are still puzzled by the motive for the crime.