The use of a Taser stun gun by police on a man who had mental health issues played a part in his death, an inquest jury has concluded.

Marc Cole, 30, died after a police officer Tasered him for more than 40 seconds on a street in Falmouth, Cornwall, in 2017.

Cole’s inquest, in Truro, heard that he had taken cocaine and was holding a kitchen knife at the time of the incident.

The police officer who discharged the Taser argued that he had feared for his own safety and believed there was also a danger Cole might have seriously harmed himself with the knife.

However, Cole’s family claim he was a gentle man who was suffering a mental health crisis. His sister, Lisa Cole, has called for a review on the use of Tasers on vulnerable people.

She said: “Marc’s tragic death has destroyed our lives and we miss him terribly every single day. What is needed is an urgent review of police use of Taser. It is too late for Marc, but we believe this would save lives.”

The inquest heard that Cole had mental health issues following the death of his father, whom he had nursed through cancer.

On the day of his death, 23 May 2017, he had taken cocaine and appeared paranoid, apparently believing that people were “coming to get him”.

Cole jumped or fell from a first-floor window and came into contact with a neighbour in her garden, causing her a superficial leg injury with the knife. Police were called and a constable discharged his Taser, activating it three times.

Initially the officer, PC Timothy Wilson, gave inaccurate information about the number of times he activated the Taser. He told the inquest this was on legal advice.

The jury found Cole had died from excess use of cocaine, resulting in paranoid and erratic behaviour, with the use of a Taser by Devon and Cornwall police having a more than trivial impact.

The medical cause of death included the use of cocaine, an episode of altered behaviour, excitement, exertion and restraint including the discharge of a Taser.

Cole’s partner, Nadine Kinder, said: “An inquest is meant to be about truth, but the only truth I remain sure of is that two innocent children were robbed of a life with their dad and me.

“Police walk around every day with people’s lives in their hands, but I now believe they are protected from the moment they put on their uniforms. Admitting giving inaccurate statements and raising more questions than they have answers, they have shown no emotion or sympathy for the family they have destroyed.

“Something needs to be done within the force to ensure that the police understand the ramifications of Taser use.”

Deborah Coles, the director of the charity Inquest, which worked with members of Coles’ family, said: “At a time when the Home Office is spending £10m on arming more officers with Tasers, this inquest has exposed a disturbing lack of understanding and sufficient training on the dangers.

“Use of force by police is disproportionately employed against those experiencing mental ill health and intoxication, the very people for whom the risks are highest.”

A spokesman for Devon and Cornwall police said: “As was made clear in the inquest proceedings, our officers were faced with a unique and incredibly challenging set of circumstances.

“They acted to prevent Marc Cole further harming himself in an attempt to save his life, despite perceiving there to be a risk of harm from Mr Cole to both themselves and the public.

“The matter was referred to, and investigated by, the Independent Office for Police Conduct, which concluded the performance of our officers did not fall below the standard expected. Our sympathies remain with Mr Cole’s family and friends.”