ANTRIM, United Kingdom (AFP) - Irish republican leader Gerry Adams, head of the Sinn Fein political party, was on Thursday being quizzed over the murder of a woman in 1972, the party said in a statement.
"Last month Gerry Adams said he was available to meet the PSNI (Police Service of Northern Ireland) about the Jean McConville case," said a statement on the party's website late Wednesday. "That meeting is taking place this evening."
The police confirmed a 65-year-old man presented himself to Antrim police station and was arrested. They can hold him for 24 hours before either releasing him, charging him or applying for more time to question him.
Mrs McConville, a 37-year-old mother of 10, was snatched from her west Belfast flat and shot by republican paramilitaries, who wrongly believed she had passed information to the British army.
In 1999 the Irish Republican Army (IRA) admitted her murder and her remains were found on a beach in County Louth four years later.
Mrs McConville's son Michael welcomed the development.
"Me and the rest of my brothers and sisters are just glad to see the PSNI doing their job," he said. "All we're looking for is justice for our mother.
"Although we didn't spend much time with our mother, we'd have liked to have spent a lot of time with her," he added.
"If the IRA hadn't have killed our mother, God knows, she still might have been alive today."
Opposed to British rule in Northern Ireland, the IRA carried out a campaign of violence during the three decades of sectarian bombings and shootings known as the Troubles Adams has always denied any involvement.
"I believe that the killing of Jean McConville and the secret burial of her body was wrong and a grievous injustice to her and her family," he said.
"Well publicised, malicious allegations have been made against me. I reject these.
"While I have never disassociated myself from the IRA and I never will, I am innocent of any part in the abduction, killing or burial of Mrs McConville."
Nobody has ever been found guilty of the murder, but former IRA leader Ivor Bell, 77, was last month charged with aiding and abetting.
The case against Bell stems from an interview he allegedly gave to researchers at Boston College in the United States.
They interviewed a number of former paramilitaries about the Troubles on the understanding that transcripts would not be published until after their deaths.
However, a United States court last year ordered that the tapes should be handed over to the Northern Irish police.
Mrs McConville was one of the so-called "disappeared", a list of 16 people believed murdered and secretly buried by republicans.
The IRA has admitted that it murdered and buried nine of the disappeared at secret locations.
Mr Adams, 65, says he was never an official member of the Provisional IRA. He has been president of Sinn Fein, the IRA's former political wing, since 1983.
The violence largely ended with peace accords in 1998 that paved the way to power sharing in Northern Ireland between largely Catholic republicans and mostly Protestant unionists favouring continued British rule.
The paramilitary group announced in 2005 that it was formally ending its armed campaign.
Mr Adams played in key role in peace talks with the British government, and on Wednesday insisted that he had "never shirked my responsibility to build the peace". "This includes dealing with the difficult issue of victims and their families," he continued.
"Insofar as it is possible I have worked to bring closure to victims and their families who have contacted me. Even though they may not agree, this includes the family of Jean McConville."
Sinn Fein continues to reject British rule in Northern Ireland.
Since the historic 1998 deal was signed, Mr Adams seemed to have completed the transformation from pariah to statesman, attending the inauguration of US President Barack Obama in 2009 and recently traveling to South Africa for the memorial service of anti-apartheid icon Nelson Mandela.