Mr Martin McGuinness has paid tribute to the gardai digging for the bodies of people murdered by the IRA.
As gardai and a representative of the Independent Commission for the Location of Victims' Remains yesterday began revisiting the six sites in the Republic identified late last week as the burial places of eight IRA murder victims, the Sinn Fein chief negotiator urged the gardai to keep looking in the sites identified.
He rejected claims that the IRA had not given enough information to authorities about the exact location of the bodies. There would be no benefit to the IRA in withholding any such information, he said.
Pinpointing the exact location of the victims had been made more difficult by changes and deaths within the IRA leadership and "geological changes".
The decision to revisit the sites comes as digging for almost a week in some cases has failed to unearth any evidence of bodies.
The commission said it would keep in contact with intermediaries and gardai in order to ensure the "best possible information is available".
Since Saturday there has been increasing concern as to the accuracy of the information, which was said to have been given by those connected with the murders to Father Alex Reid and possibly one other of his fellow Redemptorist priests. i. Yesterday at Templeton Beach, Carlingford, Co Louth, gardai again extended their search area another 10ft. The total area is now 110ft by 40ft, and they are digging down to a depth of seven feet. The dig is being watched over by the family of Ms Jean McConville who is said to have been buried there.
Gardai are digging at two sites in Co Monaghan. At Colgagh, the dig is being hampered by wetlands which had to be pumped out at the rate of 20,000 gallons of water per hour. Gardai think the remains of John McClory and Brian McKinney, aged 17 and 23 respectively when they were abducted and murdered by the IRA, may be buried there.
At Bragan, the second site in Co Monaghan, gardai have covered about 25 per cent of an area the size of a football field. It is thought that Columba McVeigh's body is buried there.
There are also two sites in Co Meath. At Coghalstown, about five miles from Navan, gardai have not yet begun digging. Special equipment is expected to be used in the search for the remains, which are thought to be those of Kevin McKee and Seamus Wright.
At the second Co Meath site, Oristown Bog, a dig started yesterday. Radar scanning equipment indicated two possible locations, and sniffer dogs have been brought in to assist gardai. The remains of Brendan Magrew are believed to be in the bog.
At Ballynultagh, near Lacken in Co Wicklow, gardai have moved their dig uphill behind the area first indicated. Yesterday's poor conditions were not helping at the exposed upland site, where the body of Danny McIlhone is believed to be buried.
