Lady Gabriella Windsor’s husband Thomas Kingston has died suddenly aged 45, Buckingham Palace has confirmed.

The financier was found dead in Gloucestershire on Sunday, with emergency services arriving at the scene after 6pm local time.

WATCH THE VIDEO ABOVE: Prince William pulls out of memorial due to ‘personal matter’.

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The news came hours after Prince William pulled out of a memorial for his godfather the late King Constantine of Greece, however it is not believed William’s move was related to the death.

Kingston was last spotted on Wednesday with his wife, the daughter of Prince and Princess Michael of Kent.

Prince Michael is the son of King George VI’s younger brother George, Duke of Kent and one of the late Queen’s first cousins.

Gabriella, who is 56th in line for the British throne, described her husband as an “exceptional man who lit up the lives of all who knew him,” The Telegraph UK reports.

“It is with the deepest sorrow that we announce the death of Thomas Kingston, our beloved husband, son and brother,” the statement on behalf of Gabriella and Kingston’s family read.

“Tom was an exceptional man who lit up the lives of all who knew him.

“His death has come as a great shock to the whole family and we ask you to respect our privacy as we mourn his passing.”

King Charles, Gabriella’s second cousin, sent his “most heartfelt thoughts and prayers” to her immediate family following the news.

Buckingham Palace said in a statement: “The King and the Queen have been informed of Thomas’s death and join Prince and Princess Michael of Kent and all those who knew him in grieving a much-loved member of the family.”

“In particular, Their Majesties send their most heartfelt thoughts and prayers to Gabriella and to all the Kingston family.”

An inquest will be held to establish the cause of death.

It is widely understood that Prince William’s absence from his godfather the late King Constantine of Greece’s memorial on Tuesday was not related to the death.

The Prince of Wales, who was set to do a reading during the service, publicly cited a “personal matter” as the reason for his absence.

While the palace provided no further explanation, both his father King Charles and wife Catherine, Princess of Wales are both unwell.

Charles has been diagnosed with a form of cancer, and is currently undergoing treatment.

Meanwhile Kate underwent some form of abdominal surgery in January and has not been spotted in public since Christmas Day.

Sky UK royal correspondent Rhiannon Mills ensured viewers that the princess was doing well as concern grew.

“We’re reassured there is no need for alarm and that the Princess of Wales continues to recover well from her abdominal surgery,” Mills wrote.

“But with the intense global interest in this family in some ways they will always face a losing battle when it comes to calming the chatter about what is going on behind palace walls. “