The renewed efforts will concentrate on sites of between half an acre and an acre in Co Wexford, within half an hour’s drive of each other and roughly a similar distance from where she was last seen alive.
Joe Blake, of the charity Trace Missing Persons Ireland which is assisting the Sinnott family, said final preparations are being made and it was hoped to open one of the sites in early or mid-September.
“We’re looking at some buildings and open farmland too. We try not to reveal the exact location for as long as possible to avoid giving anyone a chance to interfere with it,” he said.
Fiona was 19-years-old when she disappeared after socialising with friends at Butlers Pub in the village of Broadway, Co Wexford, about 16km from her home village of Bridgetown, on February 8, 1998.
Her ex-partner, the father of her then 11-month-old daughter, told gardaí he walked her back to her rented home at nearby Ballyhitt that night and left her there the next morning but there had been no trace of her since.
Gardaí have carried out numerous searches for her. At one stage they partially drained a lake and brought in divers. Six people were arrested in 2005 on suspicion of withholding information, but no charges were brought and no breakthrough made.
Her family, who twice erected memorial plaques for Fiona near where she was last seen alive, only to have them both stolen, have long maintained that knowledge of what happened to her remains in the locality and have repeatedly made appeals for information.
Earlier this year, they received information that led them to a site which they subsequently began searching in March with the help of Trace Missing Persons Ireland. The Cork-based charity provides sniffer dogs specially trained to find human remains.
“Some hair was found which was brought to the gardaí for DNA testing. They came back and said it isn’t human hair but we believe it is and we kept other samples which will be sent for testing privately,” Mr Blake said.
During that search, two people also came forward with information which brought into focus the two fresh sites that are now under preparation.
“It takes time to prepare because it’s done methodically. We run the dogs in a specific area five or six times in different weather conditions over a period of time before we begin a search in earnest,” Mr Blake said.
“That way they know the area and all its usual scents well before we begin to dig and bring fresh scents to the surface,” he said.
The work is carried out by volunteers. A machine hire company in Wexford has lent the family some digging equipment but other costs had to be met by themselves or through fundraising.
One of Fiona’s cousins, Marie Sinnott said that even 17 years after Fiona’s disappearance the longing to find her and give her a proper burial had never diminished.
“You can never lose hope. You have to believe that someone will come forward with the piece of information we’re missing. People have to live with hiding a secret and you have to wonder how long can they live like that.
“They didn’t murder Fiona and it must be a burden on them covering up for the person who did murder her and knowing they could help us bring her home. That burden can’t be getting any lighter,” she said.
Ms Sinnott said the family had requested a meeting with Operation Trace — the garda taskforce on missing women — which they hoped would take place at the end of this month. She said they hoped to convince the senior officers to take over the sites.
“They have the resources and the experience and the expertise. We went in blind on the first site and only for Joe Blake we wouldn’t have known what to do. If we have to go into sites two and three without the gardaí, we’ll do it but ideally we’d like them involved,” she said.
“If we don’t find anything in sites two and three, we’ll still keep going. It’ll never stop. We’ll keep doing whatever we have to do to bring her home.”
The Garda Press Office did not say why gardaí were not so far leading the digs for Fiona but said the investigation into her disappearance was continuing.
“A family liaison officer has been appointed. Any information which comes into the possession of An Garda Siochana will be immediately actioned,” the statement said.
Gardaí are appealing for anyone with information to contact Wexford Garda station on 053 916 5200, the Garda Confidential Line on 1800 666 111 or any Garda station.