Oren Peli -- who also directed "Paranormal Activity" -- tells TMZ that his film was done with the utmost respect for the victims of the 1986 disaster ... so much so that the group Chabad's Children of Chernobyl wrote him a letter praising him with "admiration" and "kudos" for his creation.
In a statement Peli tells TMZ, "As for the claim that our film exploits anyone -- we could not disagree more vigorously. First of all, the criticism and accusations are coming from a group that has not seen the film, whereas conversely the praise for it is coming from those who have indeed seen it."
If you recall ... Friends of Chernobyl Centers U.S. previously bashed the film for sensationalizing the tragic event -- angry over the use of victims as violent mutants.
Peli -- who also wrote the film -- lashes back, telling us ... the villains of the movie are not mutated "victims" of the Chernobyl disaster and the dilapidated location is JUST a backdrop.
He then concludes, "The film, though fictional, may in fact shine a light on a tragedy too many have forgotten."