The European Court of Human Rights has found the British government guilty of violating the right to life in the case of Derry man Mr Dermot Mc Shane.
Mr McShane was killed during riots in Derry in 1996 when a British army vehicle drove over a piece of hoarding under which he was sheltering.
The case was brought by Mr McShane’s American wife who claimed her husband was killed either intentionally or by "unnecessary" force by British soldiers who were trying to break up demonstrations.
In its ruling today, the Court said it could make no findings with regard to the alleged responsibility of the British state for Mr McShane’s death.
However, it found the British state had breached Mr McShane’s "right to life" under Article 2 of the Human Rights Convention for its failure to hold an effective investigation into his death.
The Court ruled there had been a lack of "independence in the investigation" and "the police investigation showed a lack of expedition".
In reaching its conclusion the Court described as "remarkable" the delay of five and half months in questioning the driver of the army vehicle.
It also said the inquest procedures had not allowed for any verdict or findings which "could have played an effective role in securing a prosecution should a criminal offence have been disclosed".
The Court criticised what it described as the non-disclosure of witness statements which it said had contributed to long delays.
The Derry-based Committee on the Administration of Justice (CAJ) said: "This judgement is an important step forward in terms of protecting rights in Northern Ireland and indeed across Europe."
It said: "It is a salutary reminder to government that, even in the midst of conflict, the state and its agents must act within the rule of law." The British government has always maintained Mr McShane’s death was a "tragic accident" and that there was insufficient evidence to provide a "reasonable prospect" of a conviction for any offence of murder, manslaughter or dangerous driving.
Mr and Mrs McShane were with friends in a bar close to a major demonstration in which a crowd with petrol bombs battled the RUC, and British soldiers used plastic bullets.
The court was told that at the time the group left the bar early in the morning, police and army reinforcements had been called in to counter the mob. The main aim was to move a commercial skip and a large piece of hoarding being used by the crowd as a shield.
( Additional reporting PA)