A police raid on the home of a key suspect in a violent kidnapping inquiry made a “possible” contribution to his death from a heart attack, an inquest jury has ruled.

Cyril McGuinness died after collapsing at a property where he was staying in Buxton, Derbyshire, on November 8 2019, during a series of raids in response to the brutal kidnapping of businessman Kevin Lunney in Northern Ireland.

A three-day inquest at Chesterfield Coroner’s Court ended with an inquest jury returning a finding that McGuinness, also known as “Dublin Jimmy”, died of natural causes.

The jury of eight women and three men was told that the property in Rockfield Road, Buxton, was raided as part of inquiries into “violence thought to involve criminal gang activity” but was not informed that McGuinness was believed to have organised the attack on Mr Lunney.

The jury’s narrative findings, reached on Wednesday, stated: “After hearing all of the evidence the jury finds that the entry, search and detention made a possible contribution to Mr McGuinness’s death.

“The reason for this decision is that the jury cannot completely rule out that the entry search and detention did not cause physiological stress reactions.

“However the jury wish it to be noted also from the evidence shown there is very strong indication that Mr McGuinness could have passed away at any given time due to the severity of historical cardiac conditions.

“There could have been many other contributing factors to the death of Mr McGuinness, or indeed due to the severity of his heart disease, it is a possibility that his heart failed naturally. The jury also wish to note that there were no outward signs of stress from Mr McGuinness throughout the entry, search and detention.”

The inquest, during which area coroner Peter Nieto said the raid involved a search warrant in response to allegations of “criminal gang” activity, was told McGuinness had previously been treated for heart disease.

Although the 54-year-old was not arrested during the search for electronic devices, he was detained in handcuffs under police powers permitting “reasonable restraint” during the operation.

Forensic pathologist Guy Rutty told the hearing that McGuinness died from heart disease and had no marks on his body to suggest he had been restrained excessively.

The convicted criminal, from Derrylin, Co Fermanagh, was taken ill towards the end of the search, after being allowed to smoke, drink tea and watch the television news.

The inquest, attended by McGuinness’s widow Mary, was told that he asked to go outside for some fresh air before collapsing.

Prof Rutty said McGuinness had been given a nicotine patch by police after requesting one, telling the inquest: “After about 45 minutes to 60 minutes I understand that he started to become unwell.

“He asked for his inhaler and he self-administered this.

“However, his condition deteriorated, an ambulance was called, the officers at the scene gave him first aid and he must have arrested as CPR was started.”

An ambulance got to the scene at 8.28am and arrived at Stockport’s Stepping Hill Hospital at 9.40am, but McGuinness was pronounced life extinct around 15 minutes later.

Asked to comment on whether the stress of the situation may have played a role in McGuinness going into cardiac arrest, Prof Rutty told the jury: “He could have just had a heart attack at any moment whatsoever.

“The other possibility is that the stress and the situation that he was in, ie the police entering where he was, the handcuffs… caused him to have a heart attack. Anything that increases your blood pressure or pulse rate could tip the balance.

“It isn’t possible as a pathologist to go either way. All I can say is that both are entirely possible and both relate to his heart.”

The inquest was told there was no suggestion McGuinness was “fighting against” the police or arguing with officers, with him instead being calm and compliant.

In a statement issued after the inquest, the Independent Office for Police Conduct (IOPC) said its investigation had found the force used by officers was reasonable in the circumstances.

IOPC regional director Derrick Campbell said: “Our sympathies are with the family of Mr McGuinness at this extremely sad time for them.

“We found no performance issues for any police officers involved. Evidence we gathered supported officers’ accounts that after Mr McGuinness was handcuffed he was comfortable with the process.

“He was provided with a cup of tea and taken outside so that he could smoke a cigarette.

“Prior to Mr McGuinness becoming ill, there was no evidence that the police were aware of his pre-existing heart condition.”

Three men were found guilty in November last year in connection with the kidnap and assault of Quinn Industrial Holdings executive Mr Lunney, while a fourth man was acquitted.

A non-jury Special Criminal Court in Dublin heard how Mr Lunney was kidnapped close to his home in Co Fermanagh on the evening of September 17 2019.

The businessman had his leg broken, was doused in bleach and the letters QIH were carved into his chest before he was dumped on a roadside in Co Cavan.

In its judgment, the court found that the attack was organised and supervised by McGuinness, who was born in Dublin.

During a trial which ran for 40 days, the court heard Mr Lunney was bundled into the boot of a car and driven across the border.

A Renault Kangoo van used in the attack was bought in England by McGuinness and brought to Ireland, the court said.

Those convicted in connection with the kidnapping were later jailed for between 18 and 30 years.