An extraordinary inheritance dispute between two stepsisters has been resolved after the high court ruled it could not be proved, despite pathology reports, which of their parents died first.

John Scarle, 79, and his wife Marjorie, 69, died from hypothermia at their bungalow in Leigh-on-Sea, Essex, nearly three years ago.

Entitlement to their jointly owned estate depended on the sequence of their deaths. John Scarle’s only child, Anna Winter, had to show that Marjorie Scarle was the first to die if she was to inherit the home and £18,000 in a bank account.

Marjorie Scarle’s daughter, Deborah Ann Cutler, had to demonstrate that the normal legal presumption in such cases – that the youngest person is deemed to have died last – should be upheld.

There was no suggestion of foul play. The case revolved around the rarely used section 184 of the 1925 Law of Property Act, which deals with the “presumption of survivorship” in multiple fatalities.

It states: “Such deaths shall (subject to any order of the court), for all purposes affecting the title to property, be presumed to have occurred in order of seniority, and accordingly the younger shall be deemed to have survived the elder.”

The judge, Philip Kramer QC, ruled that the inheritance should go to Cutler because it could not be proved that her mother had died first.

Delivering judgment, he referred to precedent cases, including that of two brothers killed in an air raid during the Blitz, where the order of their death affected the distribution of their estates.

In the end, the judge concluded that because the bodies of the Scarles were found in separate parts of the bungalow, where ambient temperatures were different, he could not be certain of the order of death.

Kramer said: “The only evidence which could point unequivocally to the sequence of death is the relative differences in decomposition, but does it? I am left with two not-improbable explanations for this effect. The first is that Mrs Scarle pre-deceased her husband, the second that the micro-environment of the toilet area was warmer than the lounge.”

The order of death, he added, remained uncertain and section 184 of the Law of Property Act 1925 consequently applies. Majorie Scarle is therefore presumed to have survived John Scarle and the estate followed her will and went to Cutler.

James Weale, a barrister at Serle Court chambers in London, who acted for Cutler, said it had been “an all-or-nothing case for the parties who stood to inherit from their parents”.

He added: “The reports from various pathologists … observed that [Marjorie’s] body was significantly more decomposed than John’s. Crucially, however, rates of decomposition are highly sensitive to environmental conditions.

“Having considered old case law relating to shipwrecks and WWII air raids, [the judge] accepted … that the difference in decomposition could be explained by the difference in microclimate … As a consequence, there was no basis for displacing the statutory presumption that the oldest died first.”

Rachel Liebeschuetz, a partner at the solicitors Law, Hurst and Taylor, said: “The judgment provides welcome clarification to this area of law, which has been uncertain for many years.”