LONDON (AP) — The half-sister of Meghan Markle says their father has been put in a "dangerous situation" because of pressure from the press.

Samantha Markle told Good Morning Britain on Tuesday that Thomas Markle panicked while driving on the highway because he was being followed by numerous press cars.

There are doubts about whether Thomas Markle plans to attend Saturday's royal wedding. He had been expected to walk Meghan Markle down the aisle before she marries Prince Harry but reportedly told the celebrity website TMZ he is not planning to come to the event.

Samantha Markle says her father has recently suffered a heart attack. She said he has been under an "unbelievable" amount of stress.

Prince Harry and Meghan Markle have asked for "understanding and respect" for Thomas Markle.