Jennifer Love Hewitt -- Slim Spray Fights Back ... No One MADE You Pose With Our Product!

Jennifer Love Hewitt may claim she was duped into holding a diet product in photos, but the company she's suing says that's B.S. -- and Jennifer willingly posed for a ton of pics.

As TMZ first reported, JLH sued over a product called Slim Spray, which she claims used her picture on its website without permission ... falsely implying she endorses the product.

A rep for MarzSprays, the maker of Slim Spray, tells TMZ the Ghost Whisperer was very curious about their stuff when she hit up a Hollywood gifting suite in 2012. The rep claims J.Love asked several questions about items in the suite and "posed for the camera over a dozen times with our products."

The company claims it legally purchased the images of her in the suite -- like the one above -- and insists it's on legal solid ground to use her face in ads.

As for Hewitt's claim the product bombed on "Shark Tank" -- they point out one of the sharks, Lori Greiner, DID invest ... and they were even invited back for a recent follow-up episode.