Prime Minister Tony Blair has pledged his support in helping to find the body of County Down woman Lisa Dorrian.
Lisa Dorrian's body has never been found
The case was brought to his attention following a meeting with the UUP.
Lisa, 25, disappeared after a party at a caravan site in Ballyhalbert on 28 February. Loyalist paramilitaries have been blamed for her killing.
It is hoped the remit of a forensic expert being brought in to investigate the cases of the Disappeared will now be extended to include Miss Dorrian.
North Down MP Sylvia Hermon described the development as "significant".
"I am hoping the expertise of the forensic expert coming into Northern Ireland will actually hasten the day when we recover Lisa," she said.
Last month, the British and Irish governments said the expert would be funded to help find the remains of five people abducted, murdered and secretly buried by the IRA during the Troubles.
The Irish government has said it has no problem with the scientist's remit being widened to include the search for Miss Dorrian.
The police are looking at the possible involvement of members of the Loyalist Volunteer Force in her killing.
Her family have already offered a £10,000 reward for information leading to the recovery of her body.
It was not found despite extensive air, land and sea searches