GARDAI have searched a lake close to where missing nanny Aoife Phelan, pictured, was last seen as hopes of her being found alive fade.
The dramatic development comes a week after the pregnant 30-year-old disappeared without trace.
Divers spent the day trawling a small man-made lake only minutes from a house that Ms Phelan visited shortly before she went missing.
Gardai are also in the process of examining mobile phone data in an attempt to pinpoint her movements on the night she disappeared.
Childminder Ms Phelan, who told her family she is four months pregnant, was last seen in her native Portlaoise, Co Laois, at around 8pm last Thursday.
It is understood she received a text message while visiting friends in the Colliers View estate. After receiving the message, she indicated she was going to meet someone, but subsequently disappeared.
Although the content of the text message cannot be retrieved unless her phone is found, gardai will be able to identify the sender from her phone records.
Ms Phelan's phone and bank accounts have not been used since last Thursday
On the day she went missing, she left work in Portlaoise at 6.15pm wearing jeans and a jumper with a red bomber-style jacket and black Ugg-style boots.
She left her friends at 8.10pm and hasn't been seen since.
Her family believe she may have arranged a lift from Portlaoise that night.
They also think her phone was switched off at around 9pm in the Mountmellick area.
Yesterday's search was focused on a small lake in the sprawling Kilminchy housing estate, less than five minutes' walk from the house Ms Phelan had been visiting on the night she disappeared.
Garda divers arrived at the scene yesterday morning and spent several hours searching the lake, watched by local children.
They later continued their search by wading through the reeds in an adjoining pool.
Ms Phelan is understood to have had a brief relationship with a local man who is believed to be abroad at the moment, having left on a pre-arranged holiday before her disappearance.
It has emerged that the man has been in contact with detectives, who said he is not suspected of any wrongdoing in the case.
Garda sources have told the Irish Independent they are keeping an open mind about Ms Phelan's disappearance.
They believe it is "highly unlikely" that she has fallen victim to foul play, but added that "there are big concerns for the safety of Aoife".
Officers would not comment on the diving unit's involvement in the search "for operational reasons" or specify which other locations were being examined in relation to the disappearance.
The officer leading the investigation, Supt Yvonne Lundon, said: "We are investigating all avenues in relation to information that is forthcoming and we have conducted a number of inquiries with a wide range of people who have come forward to us."
Ms Phelan worked for a family who live on the outskirts of Portlaoise.
The alarm was raised after she failed to turn up for work on Friday morning, and her family reported her missing later that day.
Members of her extended family gathered last night at her parents' home where a cousin said they had received no new information and would not be making any comment to the media.
Earlier this week, Ms Phelan's mother, Betty, made an emotional appeal on national radio for information, saying that her "bubbly" daughter's disappearance was "totally out of character".
She said: "We are very, very concerned at the moment. Aoife, if you are out there somewhere, please contact us."
Anyone who can assist gardai in their investigation is asked to contact Portlaoise garda station on 057 8674100, the Garda Confidential Telephone Line on 1800 666 111 or any garda station.