It’s the Case of the Naked Knockers.

Those who grew up in the '70s and '80s remember the never-too-shy-to-get-naked Pamela Sue Martin from her roles in The Poseidon Adventure,Dynasty, and of course, as Nancy Drew in The Hardy Boys/Nancy Drew Mysteries from 1977-1978.

The younger generation may have spotted Pamela in episodes of That '70s Show and The L Word.

In 1978 she did a pictorial for Playboy called “Nancy Drew Undraped,” and the next year she undraped herself again alongside porn icon Kitten Natividad in The Lady in Red.

But just like in some spellbinding Nancy Drew mystery, a new clue has been unearthed!

On Wednesday, Nebula’s Nude Celebs posted scans of a pigtailed Pamela in topless black-and-white shots taken from the magical time “before they were famous.”

So check them out and skinjoy, but don’t leave any evidence.

For more news of classic celeb nudes, follow Mr. Skin on Twitter!