Meghan Markle's estranged father is unable to speak after suffering a stroke, according to the US media.
Royal fans and experts in UK have already started speculating about Meghan' reaction to her father's medical condition.
A royal expert said Thomas Markle suffered a "major stroke", wondering " what compassionate Meghan Markle going to do".
Although Meghan's estranged father had long been criticizing his daughter, some royal fans think she might cancel her visit to the UK if Thomas' condition deteriorates.
Meghan and Harry are due to arrive in the UK next month to attend Queen Elizabeth's Platinum Jubilee celebrations.
Earlier, thee 77-year-old was pictured arriving at a hospital in Tijuana, Mexico, on Monday.
In the photo, the Duchess of Sussex's dad was pictured surrounded by paramedics as he lays on a stretcher with an an oxygen mask strapped to his face.
Princess Charlene and Prince Albert tied the knot on July 1, 2011 and share two children together.
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