The inquest into the death of Thomas Kingston, the husband of Prince and Princess Michael of Kent’s daughter Lady Gabriella Kingston, will look at whether his “state of mind was affected by medication”.

Mr Kingston died from a catastrophic head injury and a gun was found near his body on February 25 at his parents’ home in the Cotswolds.

The 45-year-old financier married Lady Gabriella at St George’s Chapel, Windsor Castle, in 2019 with Queen Elizabeth II and her husband, the Duke of Edinburgh, among the guests.

During a pre-inquest review hearing at Gloucestershire Coroner’s Court on Tuesday, Martin Porter KC said the Kingston family had been “advised that there could be a connection” between medication he had taken and his state of mind before his death.

Mr Porter told the court: “The inquiry shouldn’t be limited to the very final cause of death, which is clear and obvious.”

He went on to say the inquest should include “Mr Kingston’s state of mind and whether that state of mind was affected by medication he had taken”.

Mr Porter added: “In support of my submissions, the family have been advised that there could be a connection… for your court to investigate.”

The family’s lawyer told the court the possible link between medication and his state of mind “therefore justifies investigation”.

Katy Skerrett, senior coroner for Gloucestershire, said the “recent prescription… should be part of the scope”, adding: “I agree with Mr Porter, however I do caveat strongly that whether a causative link will be established is a very different matter.”

Mr Kingston’s parents attended the hearing and the court heard his father Martin Kingston will give evidence to the inquest on behalf of the family. Lady Gabriella did not attend Tuesday’s hearing.

Mr Porter said Mr Kingston’s death was “unexpected” and “impulsive”, adding: “There was no pre-planning – on the contrary there was planning for the future.”

Lady Gabriella paid tribute to her husband in a joint statement with his family following his death, describing him as an “exceptional man who lit up the lives of all who knew him”.

They described his death as a “great shock to the whole family”.

The King and Queen sent their “most heartfelt thoughts and prayers” to Lady Gabriella, who is known as Ella, and Mr Kingston’s parents and siblings.

Lady Gabriella Kingston is a second cousin of the King (Jonathan Brady/PA)

Lady Gabriella is the King’s second cousin. They are both great-grandchildren of King George V.

Mr Kingston was a director of Devonport Capital, which specialises in providing finance for companies in “frontier economies”.

The Bristol University graduate had also worked in Baghdad, Iraq, to procure the release of hostages after joining the Diplomatic Missions Unit of the Foreign Office.

He was a close friend of Pippa Matthews – the Princess of Wales’s sister – and the pair were said to have dated in 2011.

Lady Gabriella, who has worked as an arts and travel director for a brand company, is a writer and contributing editor.

She is also a singer-songwriter and released two bossa nova-inspired tracks in 2020 to raise money for charity.

The coroner indicated she wants Mr Kingston’s inquest to take place before the end of the year, saying: “I am conscious of the family having some closure before the end of the year.”

No date was officially fixed for the inquest, but all parties have been asked for availability for early December.