A former British soldier has been arrested over the Bloody Sunday killings in Derry, which left 14 Catholic protestors dead.
British troops opened fire on a civil rights march by Catholics in the city in the north of Ireland in January 1972, during the height of the Troubles.
The 66 year old who was arrested is a former member of the Parachute Regiment and is thought to be questioned in Belfast over the deaths of William Nash, Michael McDaid and John Young.
Kate Nash, whose 19-year-old brother, William, was killed on Bloody Sunday, said she welcomed the news.
"I had a call this morning from the police liaison officer that deals with our family," Ms Nash said to the BBC.
"She said that they had arrested a soldier and that he was being questioned. She said she wanted the family to know first before it went out on the news.