A “money-obsessed” GP devised an elaborate plan to kill his mother’s partner by disguising himself as a community nurse and poisoning him with a fake Covid booster jab, a court has heard.

Police initially thought Thomas Kwan used the chemical weapon ricin in an attempt to kill Patrick O’Hara, 72, at his mother’s home in Newcastle city centre on January 22.

Kwan, 53, denies attempted murder and an alternative charge of grievous bodily harm with intent.

He has pleaded guilty to administering a noxious substance but the Crown’s case is that he meant to kill his mother’s partner of more than 20 years, who developed a rare flesh-eating disease as a result of the jab in his arm.

GP Thomas Kwan court case
Thomas Kwan is accused of devising an ‘audacious’ plan to kill his mother’s partner by disguising himself as a community nurse and poisoning him with a fake Covid booster jab (Northumbria Police/PA)

Newcastle Crown Court has heard how the GP developed an “encyclopaedic knowledge” of poisons and police discovered an array of dangerous chemicals in his garage at the family home in Ingleby Barwick, Teesside.

Peter Makepeace KC, prosecuting, said: “Sometimes, occasionally perhaps, the truth really is stranger than fiction.

“The case you are about to try, on any view, is an extraordinary case.

“Mr Thomas Kwan, the defendant in the case, was in January of this year a respected and experienced medical doctor in general practice with a GP’s surgery based in Sunderland.

“From November 2023 at the latest, and probably long before then, he devised an intricate plan to kill his mother’s long-term partner, a man called Patrick O’Hara.

“On any view that man had done absolutely nothing to offend Mr Kwan in any way whatsoever.

“He was however a potential impediment to Mr Kwan inheriting his mother’s estate upon her death.

GP Thomas Kwan walks up the street
The 53-year-old GP was described as ‘money-obsessed’ in court (Northumbria Police/PA)

“Mr Kwan used his encyclopaedic knowledge of, and research into, poisons to carry out his plan.

“That plan was to disguise himself as a community nurse, attend Mr O’Hara’s address, the home he shared with the defendant’s mother, and inject him with a dangerous poison under the pretext of administering a Covid booster injection.”

Mr Makepeace said the plan involved Kwan forging NHS documentation, disguising himself, using false number plates and booking in to a hotel using a false name.

He said: “It was an audacious plan, it was a plan to murder a man in plain sight, to murder a man right in front of his own mother’s eyes, that man’s life partner.”

Mr Makepeace said the defendant will say his intention was to cause “no more than mild pain or discomfort”.

Kwan’s mother, Jenny Leung, named Mr O’Hara in her will to the effect that he could stay in her house in St Thomas Street, Newcastle, should she die before her partner.

That decision led to her having a strained relationship with her son, so much so that the police were called when Kwan burst into her home uninvited in November 2022, the court was told.

Thomas Kwan arriving at a Premier Inn on Newgate Street in Newcastle city centre
The accused is a family doctor based in Sunderland (Northumbria Police/PA)

The prosecution described him as “money-obsessed” and said he even installed spyware on his mother’s laptop so he could monitor her finances.

A year later, Kwan, who is married with a son, faked a letter from the NHS on his home computer to Mr O’Hara “with chilling authenticity”, Mr Makepeace said.

Claiming to be from a community nurse called Raj Patel, he offered Mr O’Hara a home visit, following up that letter in January.

Mr Makepeace said: “As, I suspect, would any of us, Mr O’Hara fell for it hook, line and sinker, he had not the slightest suspicion that this was anything other than a genuine NHS community care initiative which he warmly welcomed and was grateful for.”

Having stayed in a city centre Premier Inn under a false name, Kwan went to his mother’s house in a long coat, flat cap, surgical gloves and wearing a medical mask and tinted glasses, the court heard.

Posing as a nurse, Kwan spent 45 minutes at the house, carrying out thorough medical tests on Mr O’Hara and even checked his unsuspecting mother’s blood pressure when she asked him to.

Kwan, in what the court heard was broken English with an Asian accent, told Mr O’Hara he needed a Covid booster, even though he had only had one three months ago.

Mr Makepeace said: “As most of us do, Mr O’Hara averted his eyes as the nurse proceeded to dispense an injection into his left upper arm.

“Immediately Mr O’Hara felt a terrible pain and jumped back.

“He shouted ‘bloody hell’ and explained the immediate and intense pain, but the nurse reassured him it
was not an uncommon bad reaction and it was nothing to be concerned about.”

Kwan swiftly packed his things and left in a hurry, the court heard.

When Ms Leung commented that the man was the same height as her son, Mr O’Hara “began to suspect something was very wrong” and went into the street to see if he could catch the nurse, but he had gone.

In pain, Mr O’Hara contacted his own GP and found from a local hospital that the NHS organisation which had written to him did not exist.

He then went to the nearby Accident and Emergency unit at the Royal Victoria Infirmary where staff initially believed his injuries were due to a “clumsy” Covid vaccine, Mr Makepeace said.

Police tents at the scene of an investigation in Ingleby Barwick, Teesside
The investigation was focused on a house in Ingleby Barwick, Teesside (Owen Humphreys/PA)

He was sent home with antibiotics and painkillers but returned the next day when his arm had blistered and was “seriously discoloured”, the court heard.

Mr Makepeace said: “At the hospital the doctors were baffled as to what the cause of the deteriorating injury was.

“Blood tests were taken, and analysis carried out but no meaningful results obtained.

“By now it was clear to the medical professionals the infection was spreading and the damage increasing in seriousness and magnitude.

“It was clear surgical intervention would be necessary.

“It quickly became apparent Mr O’Hara was suffering from Necrotising Fasciitis, that is a rare and life-threatening, flesh-eating disease.”

Over the coming days, Mr O’Hara had diseased flesh cut away from his arm, while specialists tried to identify the poison.

“Obviously, their chances of saving his life would be all the greater if they knew what they were dealing with,” Mr Makepeace said.

“All biopsies and blood test carried out failed to identify the toxin involved.

“Mr O’Hara remained in intensive care for a prolonged period of weeks.”

The court has heard ricin has been ruled out by experts, but the exact poison used has yet been identified.

The trial continues.