The IRA is believed to have located several of the burial sites of the so-called "disappeared", those abducted and murdered over 20 years ago, and is preparing to identify the sites so they can be returned to their families.
Several sites have been found following an IRA decision last autumn to appoint a "unit" to conduct a search for those who went missing during the Troubles.
It is understood the IRA is trying to put together as precise a picture as possible before informing the families.
Logistical difficulties and the passage of time, however, have made impossible the discovery of all those whose bodies were never returned after their abduction and murder, sources have said.
As the Sinn Fein president, Mr Gerry Adams, met Mrs Helen McKendry, whose mother Mrs Jean McConville was abducted and murdered in 1972, speculation intensified last night that developments would shortly take place.
Mrs McKendry and her husband, Seamus, met Mr Adams yesterday.
Afterwards, Ms McKendry said it was the first time in 26 years that she believed republicans would help to resolve the issue and find her mother's body.
Mr McKendry said he believed Sinn Fein would do all in its power to persuade the IRA to return the bodies of those it had killed.
The Families of the Disappeared group wants information on 14 people, most of whom it believes were murdered by the IRA.
"All we asked was that Sinn Fein continue to put pressure on the IRA to return the bodies it was responsible for.
"Gerry Adams himself, and I have to say he is very sincere, is quite optimistic that we will have a return of at least some bodies quite soon," Mr McKendry told BBC Radio Ulster.
Yesterday was the first time Mrs McKendry had met Mr Adams.
In a statement afterwards Mr Adams said the issue needed to be speedily resolved to the families' satisfaction.
Families of the Disappeared also held a meeting with the North's security minister, Mr Adam Ingram, who assured the group he was giving high priority to the location of missing persons.
Mrs Margaret McKinney, whose son Brian (22) was abducted in 1978 and never seen again, said last night that while she had received no direct information from the IRA, she was "very, very hopeful something will happen now".
She was visited in her Belfast home six weeks ago by a special aide to President Clinton, Mr James Lyons, who told her he expected movement on the disappeared within months.