The full extent of the financial woes experienced by the husband of Lady Gabriella Windsor before he took his own life is laid bare today.

Thomas Kingston, a high flying financier who married into the Royal Family, died from self-inflicted shotgun wounds and his family linked his death to side effects from medication he had been taking.

But it later emerged that the 45-year-old banker had been prescribed the controversial drugs because of stress at work – which in turn was linked to debts his company had run up.

And today the Daily Mail can reveal that a final assessment by forensic accountants found that Mr Kingston’s firm will be unable to pay £8million it owes.

Mr Kingston died in February 2024 from head injuries at his parent’s home in the Cotswolds, with a gun found lying nearby.

A subsequent inquest into his death was told he had stopped taking medication in the days leading up to his death.

The inquest was told Mr Kingston had initially been given sertraline, a drug used to treat anxiety and depression, and zopiclone, a sleeping tablet, by a GP at the Royal Mews Surgery, a practice at Buckingham Palace used by royal household staff, after complaining about finding it difficult to sleep.

Lady Gabriella then warned the inquest about the side effects of drugs used to treat mental health problems.

Thomas Kingston with his wife Lady Gabriella Windsor. The couple married in May 2019

In the months leading up to his death, Thomas experienced work-related stress and sought medical assistance for trouble sleeping

Mr Kingston died in February 2024 from head injuries at his parent’s home in the Cotswolds, with a gun found lying nearby

In her statement read out by Katy Skerrett, senior coroner for Gloucestershire, she said: ‘I believe anyone taking pills such as these need to be made more aware of the side effects to prevent any future deaths.

‘If this could happen to Tom, this could happen to anyone.’

She also said: ‘[Work] was certainly a challenge for him over the years but I highly doubt it would have led him to take his own life, and it seemed much improved.

‘The fact that he took his life at the home of his beloved parents suggests the decision was the result of a sudden impulse.’

The coroner Katy Skerrett concluded Kingston took his own life and said: He was suffering adverse effects of medication he had recently been prescribed.’

It was said that his adverse reaction to medication followed a period of suffering stress at work.

After his death it emerged that the prestigious investment firm he had founded, Devonport Capital Limited, owed £27.9million.

Now it has emerged that the final residual amount left to pay back creditors was only £19.8million, meaning an £8.1million shortfall for those owed money.

Those owed cash will therefore be given 71 per cent of what they are owed – as two loans made by his company have not been paid back.

Mr Kingston with support from his family had done everything they could to save the firm, it now appears.

He had ploughed £1.6million of his own money into Devonport Capital.

And his father Martin Kingston, a respected and successful barrister, is listed as owed £162,000, of which he will receive £115,000, meaning a loss of £47,000.

Christopher Chandler, based in Dubai, was the biggest creditor and owed £12.8million of which he will lose around £3.7million.

HMRC was owed £788,226 but will receive approximately £560,000.

Devonport Capital was owed two big loans totalling £48million which administrators are still struggling to get repaid, which had impacted the company performance.

The report, which said the company was moving from administration into liquidation, was published this week.

‘It said that collecting the debts has proven far from straightforward’.

The administrators hoped a deal with a renewables business which had owed £34.57million based in India would mean cash repaid to Devonport.

But the report said that hoped-for ‘milestone payments which would have directly benefited Devonport’s creditors’ had not been received.

An African gold mine company working in Ghana still owes £2.1million and is failing to meet ‘the scheduled payments’ but is paying back between £37,000 to £74,000 a week.

A previous report said: ‘The company was initially able to continue to honour its obligations to lenders as it was still extending and being repaid on other loans, but inevitably, as time has progressed, the negative effect of the two underperforming loans on the company’s financial position has become more pronounced.’

Thomas and Lady Gabriella smile for photographers at the 2023 Wimbledon Tennis Championships 

Thomas appeared in high spirits as he speaks to Queen Camilla during Royal Ascot 2023 

Lady Gabriella met Mr Kingston through mutual friends in 2014. He had previously dated Pippa Middleton, the Princess of Wales’ sister.

He proposed to her during a trip to the Isle of Sark in 2018, and she said of their courtship: ‘I’m very happy to be with someone very special – I’m very lucky.’

They married at St George’s Chapel, Windsor in May the following year, a ceremony attended by many members of the Royal Family, including the late Queen and Duke of Edinburgh.

Following his death Buckingham Palace released a statement on behalf of Lady Gabriella and the Kingston family, which described him as a ‘beloved husband, son and brother’.

It went on: ‘Tom was an exceptional man who lit up the lives of all who knew him.’