The 53-year-old jetted into the UK with the intention of meeting the Duchess Of Sussex.
However, security at the Palace turned her away after she tried to gain entry in a wheelchair after buying a souvenir mask of her famous half-sister.
Samantha flew in two weeks after palace officials received a letter saying her behavior would 'escalate' if they did not arrange a meeting with Prince Harry's wife.
However, those please appear to have fallen on deaf ears as she was abruptly rejected without an explanation.
The two women are in dispute over the treatment of their father Thomas Markle.
A source revealed: "'This is the closest Meghan has come physically to that side of her family since she married into the royal family but palace staff had clearly been instructed not to allow her access."
RadarOnline.com previously reported that Samantha Markle was threatened with an acid attack if she visited the UK.
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The Palace did not release a statement over the snubbed visit.
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