Now that’s a dirty deed.

A Midtown porn company filed suit yesterday against a Florida man for allegedly selling low-quality bootleg DVDs of the 1981 skin-flick classic “Deep Inside Annie Sprinkle.”

Evart Enterprises claims Mark Johnston has been peddling knock-offs of its 87-minute sextravaganza since at least March 2009 under the “fictitious name” of “Shocking Videos.”

The Manhattan federal court suit seeks $180,000 in damages from both Johnston and his company on grounds of copyright infringement.

Evart’s filing notes that the film “was one of the top-five grossing adult motion pictures in 1982.”

It’s also been called “the best of the mainstream golden-age porn movies I ever made” by its buxom brunette star, who now works as an artist and self-proclaimed “sexologist.”

Evart says that its “copyright notice appears in the opening footage of defendants’ infringing copies.”

Johnston declined comment.