Gary Coleman’s ex-wife, Shannon Price, took a lie-detector test on TV over suspicions she had something to do with the 1980s TV star’s death — and the results? Buckle up.

Catch the clip ahead of Thursday’s premiere of A&E’s “Lie Detector: Truth or Deception” … where ex-FBI agent and polygraph pro George Olivo tells Shannon she flunked two of his key questions — with the results indicating some level of deception.

Shannon, for her part, stays cool as a cucumber — so much so that George repeats his findings, and asks if she has anything to say. Her response? Calmly calling his results “false.”

But George was all business — telling her flat-out he didn’t think she was fully honest during the polygraph exam, and he’s 100% convinced there’s more to the story of Gary’s demise.

Shannon — who took the polygraph test in January — was also asked if she ever struck Gary during their relationship, and whether she intentionally decided to withhold help to Gary when he fell. The results of her answers to those questions were inconclusive.

You’ll recall Shannon’s possible role in Gary’s 2010 death has been a hot topic for years — though she was never charged with anything. But with these new results, we’ll see if the plot thickens and the case stirs up fresh interest!