Coroners and juries previously applied the criminal standard to the question of whether someone had committed suicide but three appeal court judges ruled on Friday that the civil standard could apply – the test being that it was “more probable than not” that someone had intentionally killed themselves.

The ruling comes in the case of James Maughan, who was found hanging in a jail cell in Oxfordshire.

Oxfordshire coroner, Darren Salter, decided there was a lack of evidence for the jury to be sure about his intentions but offered them the chance to write a longer conclusion, on the balance of probabilities, that he had intended to kill himself.

A member of his family disputed the result at the High Court, which ruled in favour of the coroner, and has now failed at the Court of Appeal.

Lord Justice Davis said: “I conclude that, in cases of suicide, the standard of proof to be applied throughout at inquests, and including both short-form conclusions and narrative conclusions, is the civil standard of proof.”

Lord Justice Underhill said: “I think it is a pity that the law in this area has been left to develop piecemeal in the way that it has, and I … would see value in it being authoritatively stated in the coroners’ rules.”

Georgina Wolfe, a barrister at 5 Essex Court, said: “In future, it will be much easier, and thus more common, for coroners and juries to reach suicide conclusions.

“Many families who have lost loved ones will not welcome this development. As the courts have noted, suicide still carries a stigma within some religions communities and there can be financial implications, too. But, for those working in mental health and suicide prevention, a likely increase in the numbers of suicides recorded may help to persuade the government to dedicate more funding to this important work.”

But the judges did not agree that the standard of proof at an inquest should be the same for unlawful killing as it should be for suicide.

Gus Silverman, a inquest lawyer at Irwin Mitchell, said: “In the context of deaths in custody, this judgment means that coroner’s courts will apply a lower standard to determining whether a person meant to take their own life than when determining whether they were unlawfully killed, for example as a result of police restraint. It is to be hoped that the supreme court will address this imbalance.”