Meghan Markle's father is set to undergo heart surgery on Wednesday and will be unable to attend his daughter's wedding to Britain's Prince Harry, celebrity news website TMZ reported.
The gossip portal earlier reported that Thomas Markle, who lives in Mexico, was back in hospital with doctors warning his heart was "seriously damaged" after a heart attack a week ago.
Doctors "will go in and clear blockage, repair damage and put a stent where it is needed," the 73-year-old was quoted as telling TMZ, which said Markle realised it was all but impossible he would be able to walk his daughter down the aisle.
Earlier reports suggested Meghan Markle's father wanted to leave hospital to attend his daughter's wedding to Britain's Prince Harry.
Thomas Markle says he is back in hospital after experiencing serious chest pains, with doctors warning his heart was "seriously damaged" after a heart attack a week ago, TMZ said.
"I hate the idea of missing one of the greatest moments in history and walking my daughter down the aisle," he was quoted as telling the online gossip portal ahead of Saturday's ceremony at Windsor Castle.
Markle said his daughter was not angry with him for controversially striking a deal with a photo agency to stage pictures of him getting ready for the big day.
The wedding plans were thrown into turmoil amid reports that Markle's attendance was in doubt following the paparazzi scandal, rocking the royal family's meticulous planning for the event.
Kensington Palace pleaded in a statement for "understanding and respect" during a "difficult situation" as US media reported Markle had suffered a heart attack brought on by the fallout from the photo row.
TMZ had initially reported that Markle had decided against travelling from his home in Mexico to accompany his daughter down the aisle on Saturday due to his health - and to spare her further embarrassment.
Kensington Palace did not confirm whether he had pulled out of the wedding at St George's Chapel in Windsor Castle, but its brief statement hinted all was not well.
Markle accepts that the idea for a photo shoot of him preparing for the wedding was "stupid," according to TMZ, but not serious enough to keep him from making the trip to England if he gets the all-clear.
He had earlier petitioned doctors to discharge him, he said, although he has had no firm decision either way.
"Of course I'd walk her down the aisle. This is a historic moment. I'd like to be a part of history," he was quoted as saying.