12:39 PM PT -- A rep for Simon tells TMZ, "Simon believes the family is just trying to insert themselves in the narrative for publicity after the show’s success. Simon also legally changed his name in 2015 and looks forward to this getting thrown out in court."
Simon Leviev -- AKA the "Tinder Swindler" -- is now in the crosshairs of the extremely wealthy diamond-titan family that he pretended to be a part of ... they've just filed a criminal court complaint against him.
Guy Ophir -- lawyer for the true Leviev family -- says charges were filed Monday morning in Israel against Simon, telling us justice must be served for the malice brought against the Leviev name.
The legal docs -- obtained by TMZ -- outline the ways in which Simon allegedly took advantage of the family, including most notably changing his name from Shimon Yehuda Hayut to Simon Leviev to give the appearance of wealth ... Simon claimed to be a part of a wealthy family, with ties to the diamond industry.
Ophir tells TMZ ... according to Israel law, only the state can file criminal charges ... but there is an exception to the rule -- in cases of "Malice Defamation" like this one.
In these cases, the person that was hurt can file a private criminal charge and ask for criminal punishment. By using the Leviev family name, Ophir claims Simon committed malice defamation and malice invasion of privacy.
He says this is the first step in an "all-out legal war" that the family's instructed him to unleash against Simon and everyone that will join venture with him -- past, present and future.
Ophir mentions, "The Leviev family intend[s] to donate the money that they will receive to all the victims of his crimes."
We have reached out to Simon's team ... so far no word back.