The inquest into the IRA’s Guildford pub bombings, which killed five people in 1974, is to be reopened and completed more than 40 years after it was suspended, the Surrey coroner has ruled.

The decision by Richard Travers follows campaigns by relatives of the victims, survivors, and those wrongfully convicted of the attack on the Horse and Groom pub.

The inquest was halted after the so-called Guildford Four – Gerry Conlon, Paul Hill, Paddy Armstrong and Carole Richardson – were jailed for the bombings in 1975. They were not released until 1989 when the court of appeal finally quashed their convictions and recognised the miscarriage of justice.

Four soldiers – Caroline Slater, 18, and Ann Hamilton, 19, of the Women’s Royal Army Corps, and Scots Guards William Forsyth, 18, and John Hunter, 17 – along with a civilian, Paul Craig, 22 – were killed in the no-warning blast on 5 October 1974. The Horse and Groom was known as an army pub and therefore targeted by the Provisional IRA.

A second gelignite bomb was detonated half an hour later in the nearby Seven Stars pub which had by then been evacuated. There were no further serious injuries. The IRA belatedly claimed responsibility for both attacks which were carried out at the height of Northern Ireland’s Troubles.

A resumed hearing into the November 1974 Birmingham pub bombings has already begun gathering evidence. After a legal challenge, the coroner in that hearing ruled the suspects in that IRA attack would not be named.

In his ruling on Thursday, the Surrey coroner said his hearing would examine details such as the location and precise time of the blast, who was with the victims at the time, whether the victims died immediately and the response of the emergency services. He does not intend to identify perpetrators.

Travers said: “This case is not of such antiquity that it should be considered ancient history … I am satisfied that a significant number of witnesses should be able to provide valuable evidence and that resumed inquests would be a practicable proposition.

“The original murder trial did not examine what happened immediately before or after the blast on 5 October 1974 in any great detail because the prosecution case was based entirely on [false] confessions signed by the accused.

“Very little evidence about how the deceased came by their deaths has ever been heard in public proceedings (particularly not in proceedings which can now command public confidence) and there is a consequent gap in the official, reliable public record of these matters.”

The coroner said he would convene a pre-inquest review to address the scope of the inquests, the extent of disclosure and assemble a list of “interested persons”.

The Belfast law firm KRW Law, which represents the family of Hamilton, welcomed the decision and said it would consider the coroner’s proposals for the scope of the inquest.

Surrey police has already begun cataloguing material held in relation to the bombings. In the past year it has logged more than 4,000 documents.

“The bulk of material has been in storage for more than 40 years and was archived as per the processes of the 1970s and not as they would be today in a structured, indexed and electronic format,” a force statement said. “Due to the large volume of material, it is anticipated it will take a further 12 to 18 months to complete this process.

“The case is not being actively reinvestigated or made subject to formal review at this time but once all the material held has been catalogued, an assessment will be carried out to consider whether reinvestigation is a viable option.”