The Disappeared: Human remains found in search for Brendan Megraw

Human remains have been found in County Meath by a team searching for an IRA victim missing for almost 40 years.

They were found in a drainage ditch on Oristown bog, near Kells, by contractors called in to prepare the site for forensic excavations.

The land is being examined in the search for the remains of Belfast man Brendan Megraw.

He was one of the 16 murder victims that became known as the Disappeared.

Earlier, a representative of the Independent Commission for the Location of Victims Remains (ICLVR) told BBC Radio Ulster's Talkback programme it was acting on information received from Sinn Féin.

Later, the commission said it wanted to make it clear that the information came from a long-standing republican contact.

Members of Mr Megraw's family visited the site on Wednesday.

His brother, Sean, said the remains would not be removed until Thursday, but he hoped his brother could soon be laid to rest with their father and mother.

"I'm sad, but there's relief that apparently it is Brendan - we can't be 100% but we're fairly sure it is him," he said.

"From what we've been told and where he is etc, it looks like it is Brendan.

"It was a shock this morning. I knew they were about to start searching and it was more or less while they were doing some preparatory work that incidentally they found his remains."

He said it could be weeks before the remains are formally identified.

Mr Megraw was 23 when he was abducted from Twinbrook in Belfast in 1978, and murdered by the IRA.

The IRA claimed that he had confessed to being a British provocateur and Military Reaction Force undercover agent.

Sean Megraw said for the first 20 years after his brother's disappearance the family had no idea what had happened to him.

"It was only since 1999 that we knew for definite that he had been killed, but prior to that you were nearly afraid to talk to people," he said.

Investigators from the ICLVR - set up by the British and Irish governments to liaise with former paramilitaries to find the Disappeared - confirmed a body was being recovered on Wednesday.

Geoff Knupfer, a lead forensic investigator with the ICLVR, said the team had been clearing out drains when they unearthed remains.

Analysis: Chris Buckler, BBC Ireland correspondent

Dark mounds of earth sit in piles on top of the bogland where the body was discovered.

It was found during work ahead of a concentrated search. But the diggers lie idle either side of a police forensic tent.

There is a simple police cordon on the old road that leads into the bog but the flat land stretches out in every direction.

It is an obvious reminder of the scale of all of these searches for the Disappeared.

Their bodies were never meant to be found. Republican paramilitaries buried their remains in remote areas to try to hide their crimes.

That left families always wondering, always questioning what had happened to their loved one.

For years, some even held out the hope that they might still be alive.

It is likely to be days before the body found in Oristown is identified but Brendan Megraw's relatives are praying their long hunt to find him is finally over.

It is important to remember they are not the only family still waiting to be able to hold a proper burial for people who were taken from them during the brutal decades of Northern Ireland's Troubles.

"A microscopic search of the ground will be taking place to ensure nothing is left to chance," he said.

The state pathologist is to begin the process of a post-mortem examination and formal identification.

Mr Knupfer told Talkback the commission had received fresh information from Sinn Féin in the summer of this year and as a result, a fresh dig for Mr Megraw had been getting under way.

However, Mr Knupfer said that he was "not at liberty" to go into the details of that information.

Earlier, another of Brendan Megraw's brothers, Kieran, said the family had mixed feelings.

"We still have to get confirmation that it is actually Brendan, but it's within the area that they were going to start searching, so you have to be hopeful," he said.

"It's a joy that a body has been found, but (there's) also a sense of sadness too."

There have been three unsuccessful searches for Mr Megraw, the most recent in 2010.

In August, the ICLVR announced that a new search for Mr Megraw would get under way.

They said that a "geophysical survey" would be carried out on 2.5 hectares of land.