Hilda Murrell was brutally murdered in 1984 in circumstances that have never been satisfactorily explained.

Aged 78, a retired champion rose grower and a lifelong inhabitant of Shrewsbury, Murrell was an unlikely opponent of nuclear power. But speculation has been rife for nearly three decades that her anti-nuclear campaigning and her relationship with her nephew Robert Green, a former naval intelligence officer, triggered her execution on behalf of the British security services.

Murrell was abducted on March 21, 1984, and her body was discovered three days later in remote woodland a few miles from her home. She had died from broken bones, stab wounds and hypothermia. She had been about to give evidence to an inquiry into proposals to build the Sizewell B nuclear reactor in Suffolk. Her concerns about the safety of the nuclear industry had been brewing since the late 1960s, and in 1970 she was one of the first to predict that oil shortages would lead to increased demand for nuclear power.

By the time of the Sizewell B inquiry, Murrell had become an expert in the hazards of pressurised water reactors, and believed that her relentless campaigning had put her safety at risk. She made arrangements for her papers to be kept safe in the event that anything happened to her. Green's book details events that occurred in the run-up to her murder and the subsequent investigation, and explores a second possible reason for her death: her relationship with Green himself.

Green's naval career began in 1962 at Dartmouth. After a short spell at sea, he was transferred to the Fleet Air Arm, before being promoted to commander in 1978 and sent to the Ministry of Defence as personal staff officer to an admiral closely involved in recommending the replacement for the nuclear-armed Polaris submarines. He applied for voluntary redundancy in 1981 but only heard that his application had been successful in April 1982, a week after the start of the Falklands War. As an intelligence specialist, he was assigned to the navy's Northwood command base working as staff officer to the fleet's commander-in-chief.

It has wrongly been reported that Green issued the order to sink the Argentine cruiser, the General Belgrano. He was off duty when the order was given. Allegations that Prime Minister Margaret Thatcher had ordered the attack on the Belgrano to prolong the war gathered pace after the conflict ended, and Green, who left the navy in late 1982, was suspected of leaking information used by campaigners. The fact that he was close to Murrell lent weight to the suspicions, though he was quickly exonerated.

Twenty-one years later, labourer Andrew George was jailed for Murrell's murder. He had been 16 at the time of the killing, and was remarkably unlike any of the photofits and descriptions of the man seen driving Murrell's car away from her house on the afternoon of her abduction. Green has never believed in George's guilt, and has campaigned tirelessly for the real killers to be brought to justice. This book is the latest step in his campaign. His quest for truth has been supported by Tam Dalyell, Michael Mansfield QC – who has written the foreword to the book – former police officer John Stalker, and former MI5 agent Gary Murray, among hundreds of others.

Green has written an excellent, detailed account of the murder and the subsequent decades of digging, often hampered and threatened by official and unknown opponents. The best tribute that can be paid to Hilda Murrell is to buy this superb account of the search for the truth about her death.