Gary Goldsmith hasn't spoken to Catherine, Princess of Wales "in years".
The 59-year-old businessman is the uncle of the future queen of England - who is married to William, Prince of Wales and has Prince George, 10, Princess Charlotte, eight, and five-year-old Prince Louis with him - but admitted that he sees more of her sister Pippa Middleton, 40, her brother James Middleton, 36, and only checked in with his own sister Carole during the Princess' recent spell in hospital.
Speaking on UK TV show 'Good Morning Britain', he said: "I've not spoken to Kate for ages...years...or maybe a year. Weddings and funerals, unfortunately. We don't really get to see them that often. Pippa, moreso, James, moreso. And my sister, I checked with when Kate was in hospital."
Over the weekend, Catherine thanked the public for their "continued support" since she underwent surgery.
The 42-year-old princess - who underwent abdominal surgery on January 16 - has broken her public silence via a Mother's Day message posted on Instagram.
Alongside a family photo - which features the princess and her three children - a message reads: "Thank you for your kind wishes and continued support over the last two months.
"Wishing everyone a Happy Mother’s Day. C (sic)"
Prince William took the photo at Windsor earlier this month.
The princess underwent surgery in January and Kensington Palace previously confirmed that she's unlikely to return to public duties until after Easter.
The Palace said in a statement on January 17: "Her Royal Highness The Princess of Wales was admitted to hospital yesterday for planned abdominal surgery. "The surgery was successful and it is expected that she will remain in hospital for ten to fourteen days, before returning home to continue her recovery. Based on the current medical advice, she is unlikely to return to public duties until after Easter.
"The Princess of Wales appreciates the interest this statement will generate. She hopes that the public will understand her desire to maintain as much normality for her children as possible; and her wish that her personal medical information remains private.
"Kensington Palace will, therefore, only provide updates on Her Royal Highness’ progress when there is significant new information to share.
"The Princess of Wales wishes to apologise to all those concerned for the fact that she has to postpone her upcoming engagements. She looks forward to reinstating as many as possible, as soon as possible."
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