GARDAI have retrieved data from the mobile phone of murder victim Elaine O'Hara that could be crucial to their investigation.
It comes as the garda net is closing in on a man suspected of murdering the childcare assistant.
The Irish Independent has learnt that detectives are making "good progress" since they found her mobile phone in Vartry Reservoir near Roundwood, Co Wicklow, on Tuesday.
The phone was one of a number of items recovered during searches of the reservoir and officers were concerned that it had been damaged.
But they confirmed last night that the phone did belong to Ms O'Hara (pictured) and that they had been able to gain access to records of her calls and texts.
Gardai believe an examination of the data will help them pin down the identities of people she was in contact with in the days and weeks prior to her disappearance in south Dublin in August last year. Investigators were hopeful that when combined with their trawl through 1,600 hours of footage from CCTV cameras in a series of locations, including those close to her home at the Belarmine complex in Stepaside, Dublin, they will be able to make substantial progress with their inquiries.
Gardai think the 37-year-old met her killer within a few hours of leaving her home at 5.05pm on August 22 last year and they are also trying to find out if she had been in his company previously.
She may have met her killer on an internet website as a result of shared interests, officers believe.
It is understood investigators have identified a potential suspect who had been in contact with Ms O'Hara on the phone up to the evening when she vanished.
However, sources have stressed that the individual is from a group of up to five suspects who had been using a specific website through which they made contact with the murder victim.
"The investigation team is making good progress and the number of suspects has narrowed down significantly. However this could be a long and difficult investigation," a source said.
Gardai have established that Ms O'Hara was an active internet user when they checked her computer after she was reported missing last year.
This has become a key focus of the investigation since the discovery of part of her remains in undergrowth, off the Killakee Road, in the foothills of the Dublin Mountains yesterday week. Searches of the area are continuing in an effort to locate the skull, which could help determine how she died.
Yesterday officers widened the area of their fingertip search in a 30-metre radius of where a small number of bones were first found.
An initial post-mortem examination of the recovered remains by deputy State pathologist Dr Michael Curtis was unable to establish the cause of death and the result has been left open, pending further garda inquiries.
In the meantime, gardai have been describing her death officially as suspicious but the case is being given the full resources of a murder investigation.
Gardai said last night they were continuing to receive a good response from the public.
Officers again appealed to anybody who might have been aware of new friendships she had developed in the days prior to her disappearance to contact them at the investigation headquarters in Blackrock station or on the confidential phone line, 1800 666111.
By Tom Brady and Paul Williams