Meghan Markle Caught Up In Shocking Drug Scandal!

Meghan Markle has been dragged into an ugly drug scandal — by her father!

A month-long investigation in Mexico by RadarOnline.com can exclusively reveal Thomas Markle Sr. has bankrolled Meghan's secret "sister" — a meth addict who vanished after hitting him up for $6,000 in cash.

Insiders told how the Duchess of Sussex's embattled dad doted on 38-year-old Lori Davis and treated her like his own flesh and blood.

"Jocelyn was like his grandchild. She called him 'Uncle Grandpa,'" explained Sandoval, a construction worker.

Thomas and Davis were so close she drove him from the hospital in May when he underwent a cardiac procedure that prevented him from attending Meghan's wedding to Prince Harry in London.

But after Thomas lavished them with gifts, Lori took advantage of his generosity and weaseled a $6,000 loan out of him. Then she coldly cut him off and even snubbed his 74th birthday on July 18, according to her ex.

"The last time Tom saw Lori and spoke to her was when he gave her the money," Jose revealed. "Tom is a great guy, but he's lonely. To Lori, he was like a sugar daddy. He's lost Meghan and now he's lost Lori, too. But he's worried about her — just like he's worried for Meghan."

Sources in Rosarito confirmed to RadarOnline.com that Davis had not returned to town at the beginning of August, and claimed she took two dogs belonging to another friend when she suddenly disappeared! Her cruel snub comes soon after a heartbroken Thomas talked about how it might be "better for Meghan" if he were to die.

But the scandal isn't the first time the Markle name has been dragged into a drug controversy. Meghan's dad has admitted to having used drugs but insisted he hasn't done anything "for more than 20 years."

The former actress' nephew Tyler Dooley, 26, is a legal cannabis farmer in Oregon and trades off the family name by growing a strain of marijuana called Markle Sparkle.

"Meghan's already livid about her family's loose lips, but she can't believe her father would associate with a known drug addict," a royal insider said. "It's reckless beyond belief and only makes the rift between them wider! Meghan loves her dad, but she thought he was more streetwise than to be taken for a fool by a desperate young druggie."