Specialist Garda teams will resume searches of bog-land in the midlands later today as part of Operation Trace, established to investigate the disappearance of six women from the greater Leinster area.
Yesterday's searches were concentrated on Creggan, just off the Athlone-Moate road and Kilbride bog which is close to Clara, Co Offaly, and less than 10 miles from Creggan.
Another search is being made of a wooded area at Kilsheelan, near Clonmel, Co Tipperary.
Supt Joe Shelly, Athlone, said the Creggan and Kilbride searches were being carried out in the belief that the body of a female may be buried there.
"We are acting on information received and we must follow up on these leads until they are exhausted," he said.
The searches were being co-ordinated by the National Bureau of Criminal Investigation, he added. Sources indicated that the information has come from a convicted teenage prisoner from the midlands, currently in custody in Dublin.
At the Creggan site, which is afforested cutaway bog, more than 35 members of the force were digging in specific locations for the body. They were also using a mechanical digger.
There are more than 10 acres of bog on the site, which adjoins the Dublin-Galway road. Members from the Garda Underwater Unit probed the many bog-holes on the site.
The Clara search, which was organised from Tullamore Garda station, was less extensive, with more than 15 members searching a boggy area near the town.
Operation Trace was set up to refocus the investigation into the disappearances of Ciara Breen, Jojo Dullard, Fiona Pender, Annie McCarrick, Fiona Sinnot and Deirdre Jacob.
Joe Humpreys adds:
In a separate development, a serial killer serving 11 life sentences in a Canadian prison has contacted the Garda claiming to have information about the disappeared women.
Clifford Robert Olsen (59), who was convicted in 1982 for murdering 11 children and young adults in a two-year period, told gardai he held letters from an alleged accomplice in Dublin who had murdered five women. The letters purport to contain details of the murders as well as the burial sites.
A Garda spokesman confirmed yesterday that Olsen had been in contact from his prison cell in Quebec with gardai in Co Kildare who are co-ordinating the operation and they have sought the relevant documents from Olsen.
Detectives are sceptical, however, about the authenticity of the letters as all information received so far from Olsen could have been sourced from the Internet.
A Garda spokesman stressed the searches already taking place are not related to Olsen's claims.