GARDAI do not suspect foul play in the case of a 39-year-old woman who vanished without trace nine days ago.
But officers are "gravely concerned" about the well-being of Monica Riordan, originally from Finglas, in north Dublin, who went missing after leaving the Dublin city centre office where she works for the government agency Pobal.
Searches of the Grand Canal and the River Liffey by gardai failed to yield any breakthrough in the investigation.
Officers have also examined a second mobile phone which they believe was owned by the missing woman.
It is understood that this phone was discovered in her place of work.
CCTV footage has also been found by gardai showing Monica near her place of work on the day she disappeared.
Monica, who lives with her partner in Navan, Co Meath, attended work as normal on the Tuesday morning she disappeared, but it is believed she left her office on Holles Street at about 11am.
Her mobile phone was subsequently handed in to gardai by a passer-by who found it near Grand Canal Street.
Gardai said Ms Riordan had made several calls to the emergency services with her last call made at 4pm on the day of her disappearance.
Since her partner reported her missing, gardai have been trawling through hours of CCTV footage in the vicinity.
In an interview, a relative of the missing woman said: "Gardai told us they have CCTV footage of her outside Spar on Hogan Place which is very near to where she works.
"That footage is her last known sighting. That's all we have for now. They're still looking at CCTV.
"The police haven't stopped working since her disappearance and they're still chasing yet more CCTV. It's very time consuming.
"We've heard absolutely nothing and we have no clues to go on. It's a mystery. Christmas was incredibly difficult for all the family because we still haven't heard anything."
Monica is of average height and of thin build with shoulder-length blonde hair.
When last seen she was wearing a long grey coat, dark jeans and grey/white runners.
Anyone with information is asked to contact Pearse Street garda station on 01-6669000.