IN a stunning turn of events, former “Growing Pains” star ALAN THICKE has been rocked by a brutal kidnapping and murder plot!

The 66-year-old actor was said to be floored when he learned that his mother-in-law has been ac­cused of orchestrating the gruesome slaughter of her wealthy husband near Santa Cruz, Bolivia.

“Alan is shocked by the news and deeply troubled by what may have happened,” said an insider.

“Right now, he doesn’t know what to think. He’s just waiting for the local authorities to complete their inves­tigation.”

Miriam Callau, the mom of Thicke’s third wife Tanya Callau, has been charged as the mastermind behind the March 28 disappearance of her Dutch husband Petrus Jacobus Gerardus Dekker, Tanya’s stepfather, from their $3 million, 1,400-acre cattle ranch in the South American country.

Dekker’s decomposing body was dis­covered more than a week later in a field about 1,100 yards from the home the couple had shared.

He was shot four times – twice in the chest and two times in the head, according to police reports.

A local worker reportedly confessed to authorities that 64-year-old Miriam, also known as “Chingui,” paid him $4,000 to make her husband “disappear.”

He said he contracted two hit men, who bound Dekker’s hands and feet with leather lacing, smashed in his head and shot him before dump­ing his body in a pasture to rot.

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