TLC's 'Waterfalls' -- We Were BLOCKED From Using Left Eye on Remake

TLC says their remake of 'Waterfalls' with a Japanese pop-star was NOT a slap in the face to Lisa 'Left Eye' Lopes -- in fact, they claim they weren't allowed to use Lisa's rap, because they don't own the rights.

TMZ broke the story, Lisa's family was upset when TLC released the 20th anniversary addition of arguably one of their biggest hits ever -- and axed Lisa from the track ... replacing her with J-Pop queen Namie Amuro.

But remaining members Chili and T-Boz are setting the record straight ... claiming the band doesn't own the master recording rights to Lisa's rap, and all requests to gain the rights have been DENIED.

Chili tells TMZ, "We were forced to use a creative way to honor Lisa's memory and celebrate this milestone with the fans."

TLC also says they reached out to Ron Lopes -- Lisa's brother -- before releasing the track.

TLC adds, "We have and always will protect our sister’s legacy as TLC consists of the three of us collectively ... there will never be a replacement for Lisa or any members in TLC."

Now, here's the remake -- sounds a lot like the original, except for Lisa's rap, of course ...